Category Archives: music

Le Damassama à l’Opéra de Lille

Le Damassama, œuvre interactive que j’avais co-réalisée l’année dernière, sera à l’Opéra de Lille le 12 Mai de 12H30 à 18H00 !

L’opéra fait régulièrement des journées intitulées Happy Day où le public est invité à découvrir des mini-concerts et spectacles dans les différents espaces du bâtiment, ainsi que des installations : c’est donc l’occasion de découvrir ou redécouvrir cette installation.

Pour ceux qui n’auraient jamais entendus parler de l’installation, voici sa description, par Léonore :

Amphithéâtre de bols tibétains, le Damassama réserve au visiteur la place de chef d’orchestre, initiateur par sa gestuelle de réactions instrumentales (par capteurs interposés) invitant à un cheminement musical personnalisé.
Le vécu de l’expérience sonore de l’instrument suscite l’écoute attentive, introspective des dimensions de soi, des autres et de l’environnement personnel. De simples auditeurs, nous devenons instrumentistes et recréateurs de l’univers sonore.
Lors de l’intervention, les vibrations pénètrent le corps et y persistent, incitant à écouter le monde dans une réalité spirituelle dont nous sommes les auteurs sur l’instant.

PulseAudio network transports + Wifi

Now that I have an idea of a cool hardware for listening to music, I’ve been experimenting with pulseaudio network support. Over Wireless.

They are two ways of using pulse for network streaming : RTP and TCP. The first one was a total failure for me (using pulse 1.0). The second, however, was very straightforward to setup and is almost working perfectly. I only get micro-interruptions every 10 seconds. But that’s enough for not being suitable.

First, the upload rate is about 200kb/s, so maybe that’s too much for a cheap wireless card (I’m using the ath9k driver). According to Lennart, the problem is partly due to pulse not compressing streams over the network. One possible solution is to use the CELT codec (from Xiph), which has been designed to produce high fidelity audio with very low latency and power consumption. CELT’s features are the following:

  • Ultra-low latency (typically from 5 to 22.5 ms)
  • Full audio bandwidth (≥20kHz; sample rates from 8 kHz to 48 kHz)
  • A quality/bitrate trade-off competitive with widely used high delay codecs
  • Stereo support
  • Packet loss concealment
  • Constant bit-rates from 32 kbps to 128 kbps and above
  • A fixed-point version of the encoder and decoder (interesting for embedded boards)

Given the random network latencies, I can assume we have around 2ms using a wifi connection, plus pulse and celt, that would be something around 10ms… which would still be pretty ok. Having this would make a close alternative to Apple’s RAOP protocol that uses ALAC. Still, ALAC is lossless while Celt is limited to 128kb. So, FLAC or ALAC itself maybe ? Even if it eats more processing power, for desktop and powerful boards, that would still make sense.

To prevent multiple encodings/decodings, another trick would be to implement a server-side decoding and therefore write module for PA that supports speex, vorbis, etc. But that’s another story.

Second, this could also be a jitter/latency problem. In fact, I’m a bit more convinced this is the real problem. According to Maarten Bosmans, there’s still room for improving these things in the pulse core ; so that’s good news. I don’t understand why my wifi N card, if I’m not doing anything else, wouldn’t be able to keep up with the 200kb/s rate. But that’s only intuition here.

Conclusion: before going further, I’ve to understand first if this is a latency or bandwidth-related problem to pick the right fight.

Damassama @ Panorama 13

Durant ces dernières semaines, j’ai co-réalisé un projet nommé Damassama, une installation d’art numérique à l’initiative de Léonore Mercier. Le travail s’est réalisé en coopération avec l’équipe de recherche MINT, de l’Ircica. Maintenant que l’installation est terminée, vous pouvez aller l’essayer jusqu’au 24 Juillet au Fresnoy (Tourcoing), durant l’exposition annuelle Panorama (#13 cette année). Petite présentation de cette installation :

Damassama est une installation constituée de deux plans disposés en demi-cercles sur lesquels reposent des bols tibétains. Des marteaux frappent sur ces bols afin de les faire sonner, et ces marteaux sont activés grâce à la gestuelle de votre corps. Vous vous placer au centre de cet amphithéâtre et pour déclencher un bol, il suffit de tendre le bras dans sa direction. Pour faire une montée de gamme, vous pouvez balayer avec vos mains devant vous ou encore lancer vos bras pour un accord. Le tout étant harmonisé sur une gamme orientale, on se prend vite au jeu de créer des atmosphères un peu mystiques !

Côté technique, le seul capteur utilisé est une Kinect. A coup d’OpenNI, Mididings, Jack, Python, C++ et j’en passe, nous avons pu relever le défi de réaliser cette installation complexe, ce qui n’était pas gagné d’avance :-)

Bref, je vous laisse visionner les quelques photos, ça vaudra mieux qu’un long discours…

Composing with (Tux)Guitar(Pro)


A few weeks ago, I’ve started trying to use the free tablature editor TuxGuitar. It’s a clone of Guitar Pro written in Java and available for Linux, MacOSX and Windows. Basically, it works, but hell, this is really no fun to use. You start playing a riff on your guitar, then you want to translate it onto a tab and it takes ages before you get the perfect timing.


A friend showed me earlier a new software called melodyne, and have to say, it’s quite impressive. The idea is to read an audio file, analyze it and find out the notes that were played. The result is therefore a score and you can change the pitch and length of any note, transpose them to a new scale, etc. With this example, I wanted to show that we do have the technology to extract notes from an analogical music stream.

Roland GK-3
Roland GK-3

Indeed, we have it, and Roland did not wait for melodyne to make some interesting devices such as the GK-3. It’s a device you add to your guitar and it produces the corresponding MIDI signals. They have also made some devices to go along this one such as the GR-20, which can synthesize a plethora of instruments (e.g. sitar, piano, …).

Ok, but the downside of the Roland approach is that you have to buy and attach a device to your guitar. This device uses a dedicated microphone, which can read the strings independently, therefore simplifying the signal analysis. Moreover, the GK costs about $200 and it’s more than twice for the GR…

Back to the original topic, what I’d like to have is the ability to plug my guitar in the sound card, play my riff so that it writes the notes to the tablature editor as if I had a MIDI guitar… but without adding any device. This may be quite complex to be able to do realtime analysis, but I guess it’s worth trying.

Using keyboard to play
Using keyboard to play

Another much easier way to do that would be to, at least, have a way to tap the notes on the keyboard. Maybe you can already do that by using the MIDI input of the tablature editor and by using a virtual keyboard connected to it. If so, why isn’t this integrated into the tablature editors ? This is rather boring to use the mouse and the keypad to write music, really. So, basically, you would play FretsOnFire with your keyboard (using enter and F1/F2/Fx keys) to give the rhythm.

Anyway, since I’m quite lazy, I don’t want to use the mouse and keypad anymore for this task, so I’ll investigate these ideas a bit as soon as I can allocate time. Oh, and if you know about some software or combinaison of software that can do that, I’m really interested in knowing them (and also scientific publications).

Lymbago, final round (Day 7)

cons_monitorOk, sorry for the late post, but I wasn’t there at the beginning of the week.

Basically, we completed everything. Yeah really. Just on time :-) Celltool was our target of choice for the morning and from the afternoon, we worked on HJ and Salami.

bowo HJ was difficult to complete because of the bow. We have tried to find the same ambiance as recorded at Arras, that was clearly not easy.

mehdi_poseSalami was easier than expected and Mehdi managed to find a solo in a reasonable amount of time. Anyway, we still have a few things to record, but that’s really bonus. We have the essential. Mission complete ! :D

What I can say is that was a really great experience. Very intense but I think we were all happy to live it, that was just fucking great. Also, we’re all happy with the result, which is just awesome.

To try to sum up this crazy week, here are a few numbers of what happened, in random order :

  • 19+ Pizzas
  • 37,2 Gb of music (!!)
  • 1 dead hard drive
  • Litters of shit soda
  • Around 15 tracks per song
  • Litters of coffee
  • 7 days
  • Around 100 hours of work (!!!)
  • 1 BBQ
  • A few beerspizza
  • 7 Songs
  • 10+ Pasta boxes
  • 50+ Cables
  • 1 unusable bass
  • 1 unusable amp
  • 13 Microphones
  • 9 Guests

Of course, we now have another BIG work to complete : the mix. People are used to say this formula : “One day of recording equals to two days of mix”. Considering that we spent about 15 hours a day, we therefore have around 30 hours of mix per song. So… we have 7 songs, 7*30, result : 210 hours of mix. *GGG*. So, you now understand why the album can’t be out in a few days. We really still have a lot of work.

I’ll try to update this blog as soon as we make some progress on the mix, so keep an eye on it ! :-)

Rock’n’roll !

PS: For the specialists, the Tubefire8 and Ardour worked very well and I’ll use them for sure during the next session !

Lymbago is just awesome (Day 6)

Saturday, week end. No rest, no mercy !

We’re all late this time, but we reached the studio as fast as we could. We opened this day with a beautiful riff coming from the acoustic guitar. Beautiful & intoxicating tunes spread into the studio and put it into an atmosphere of melancholy and seriousness. Nobody was talking. mehdi_acc_blubThis acoustic guitar was played by Mehdi and this was of course the Nouvo riff…

This day was smooth. Maybe the smoothest we had. Nouvo was recorded and finished at 5:39PM, then followed Ttta at 8:50PM. Louis & Mehdi did a good job. So at this moment, we had 4 songs completed, just awesome. So awesome that we made you a preview of the end of Ttta ! Beware, this is total preview, the sound is very raw, expect a much better one on the album.

We also had the visit of Diego’s brother and some of his friends. They brought their energy with them (even if they have missed Mister Moreno at the “Cabaret Vert”, hehe), so that was great  :-). Btw, look at our new diet (see picture), isn’t that so delightful ? kawabull

Once these two songs were recorded, we started Salami and HJ. Louis made his part on Salami and Mehdi on HJ. The goal was to complete the fast parts on these songs, even if we had to stay very late, so that we can complete the hardest ones the next (and last) day.

We indeed did that and started recording Mehdi’s guitar on HJ at 1:29AM… and finished around 3AM.

state2At least, only one hard song remains (Celltool) and 2 hard parts : the bow on HJ and the big solo on Salami.

See you next day with a happy end I hope ! :-)

Lymbago and the (dying) Lady of the Lake (Day 5)

Alarm, Shower, Shoes, Car, Road, Studio. Standard.

brunetti As planned, we took the Brunetti to the studio. We tried it and it revealed to be perfect for the sound we were looking for. I don’t need to precise how relieved we felt. Good point !

But we didn’t record this morning, we preferred to dedicate it to a rehearsal in order to finish all the remaining issues of the songs. Since there’s a lake just behind the studio, this was obviously the best place to go and get inspired. After a few hours, Louis, Mehdi & Diego came back with everything wrapped up.


Around 12AM, we calibrated again all the amps to be sure we were safe for the rest of the recordings. Then, we jumped to the recording. Louis and Mehdi managed to record successfully Stomach and we added some parts to get a richer sound. I don’t tell you more, you’ll discover it with the album :D. Around 8PM, Stomach was done.

louis_gratteThen started a nightmare. We started to have many xruns during the recording. Xruns are basically desynchronization with the soundcard that makes the sound crack. After a few minutes, I realized that the disk was full. Ok. Shit. Let’s move some stuff to the backup device. What ??? The backup is just dead. Yeah, the hard disk decided to stop displaying its contents and we couldn’t write anything nor read on it. The bright side of the story is that I always make two backups. So, yes, we had another drive with to save us :D. We therefore lost one hour replicating the hard drive (we have more than 30Gb of data at the moment) to another, to be safe again.dead_hdd But ok, we could go on with the recordings.

We finished Blub around midnight and we added a bit of acoustic guitar, which, I have to say, make some parts of the song really better !

back_roadAnd then, as every night, we came back home… knowing that only two days remain to complete that. Waho !

Lymbago, from dawn till dusk (Day 4)

Fuck. I’m late. It’s more and more difficult to wake up on time for us, we’re accumulating the effects of many missing hours of sleep (we do about 15hours of studio per day…). Hopefully, the spirit here keeps us motivated and we’re doing everything we can to succeed.

We have three guests today : Laurine, Chloé & Elvina ! Cheers :-)

diDo you remember our DI box problem yesterday ? We were very lucky. I was near the Gambetta metro, waiting for Laurine and I met a friend who works at the Euroguitar shop. He could sell me a DI before the shop opens. Yeah !

The morning was dedicated to finish the bass. We planned to finish around 3PM and… we finished at 6PM. Hum. Anyway, Diego managed to record everything even if some songs (especially HJ) was, as expected, an obstacle course for him.

It was time for Louis to start recording. He did Stomach fast and we were happy with the sound. To save a bit of time, I then decided to record both guitars to finish the songs one by one.

orange_ampWe therefore moved the Orange amp of Mehdi to the big room so that he could get a better sound. After a few minutes of micro placement, we indeed managed to get a great sound. Louis was jealous. Yeah really :D. That’s right, Mehdi’s sound was much better. So, we moved his amp to the big room too. The problem is his sound was still the same… I therefore fired the jamin500visual scope and we found the problem : his sound was, again, very low in the mediums. After spending minutes (hours?) of tweaking his GT-6 pedalboard and his amp, we couldn’t get the sound we wanted.

We therefore decided to give up and bring my Brunetti amp the next day and use it instead of Louis’ amp.

At this point, we couldn’t do anything better, so we came back home knowing that the following day was going to be very busy.

Lymbago, gogo bass ! (Day 3)

And… another new day. Wednesday was… kind of a dark day for us. After our daily 50 minutes of road and some chocolates, we calibrated the bass and configured Louis & Mehdi gears so that they can play along with Diego.
Even if we managed to find a good sound for the bass, we encountered a big problem : the old bass of Diego gave a weird sound and his new one added strange ones : result we had no bass to record.


We therefore fired up our GSM & instant messaging software to borrow a bass. We contacted at least 6 guys and some shops and eventually found a good bass ! While Diego & Bertrand were out to get the bass, we started calibrating Louis’ amp.


At least we tried. First, the room where Louis is recording is so small that we had a (too) strong natural reverberation. Second, the micro for the guitar we have is a mid quality product, so we have to make sure to use it as its best. We managed to get a decent sound thanks to JR (the bassist of my band) who helped us by listening to the takes through the Internet. Still, the sound was a bit low in the medium, which is not good at all. JR therefore told us to make a direct recording of the guitar so that we can tweak the result during the mix. Err, but the problem is that we don’t have a DI box to record the guitar without going through the amp : damned.

gui_console18:51. Back to the bass, we calibrated it, got a good sound and started recording. Diego successfully recorded Stomach, Ttta and finished on Nouvo. It was 0:35. Time to go back home, totally tired…

Lymbago, Day 2

This one will be short since we’re really short on time to stick to the planning and I can’t find a single minute to write the daily reports. But, anyway, if we speed up a bit, we’re still on time !


So, Tuesday, we started recording the missing double-kick parts to reinject them in Ttta & Salami. The trick worked well. Then, followed Nouvo recording. Mehdi helped Bertrand by supporting him with an acoustic guitar.

At this moment, we therefore had 5,5 tracks recorded (see picture)

While finishing the drums, Louis, Diego & Mehdi decided to wrap up Celltool, which lacked some riffs. They went out and rehearsed.


Thanks to David, we could make a break and enjoy a good BBQ, just awesome :D
Louis also greated us with a nice pan flute concerto ! That was such a success, we decided to replace all the guitars by it. Yes, I’m serious.

The afternoon was dedicated to complete once for all the drums. HJ was the next target, and not an easy one. The support tracks couldn’t even be used since the software they use (Guitar Pro) didn’t managed to handle the rhythm switches, resulting in glitches in the audio file. We therefore recorded it live with Mehdi on the guitars as backtrack for Bertrand. Diego also rehearsed since this song is hell for him !


The last one was Celltool. This one was a nightmare ; nothing more, nothing less. We felt the pressure getting a bit more on our nerves every minute that passed. The guitarists decided to change some structures and other (not-so) details in it, so Bertrand had to find new parts in live. It’s useless to say that Bertrand ended by looking at Mehdi a bit like an enraged dog would have :D

bertrand_finishedAnyway, this day was succesfully completed, with all the drums done and an exhausted, but happy drummer !