I’m Airto Moreira’s fan

…or, to be more specific, I'm fan of his five tracks, no more, no less. I had once a magnetic tape from my father with 4 tracks of an unknown artist. I listened to them for years and never stopped wondering, who could've made such a record. Finally, someone on the newsgroups said that it might be Airto. In fact, those four tracks came from the "I'm fine, how are you?" album. I was expecting a lot more and I found… just one track, a fifth from the same album. The remaining 3 tracks are so much worse that it really makes me wonder how the heck do they happen to be on the same album. I also sampled the new album, "Life After That", which was a disappointment.

Those five tracks are apparently recorded with a complete band, consisting of experienced jazz musicians. This base gives with Airto's Brazilian instruments and rhythms a solid base. And I think he needs it. The "Live solo" from "Live After That" has a funny beginning, but the rest sounds rather pathetic, unless you smoke dope.

And it's not like I don't like Airto, I really do! Just look on his profile on last.fm, I'm his top fan (at least at the time of writing). I just don't get, why are his records so uneven.

JBL Creature II

Thirsty of nice stereo sound, I bought JBL Creature II Speakers. I like the idea of having 3 speakers: one big speaker for low, indirectional frequencies and satellites for directional middle and high range. Specialized speakers can do the job better than one speaker that tries to generate the whole range and fails. Having only one low frequency speaker is also a good idea. Why have two things of the same kind when just one is enough? Of course, this is not true for satellites, since they need to cooperate to create the stereo sound.
At first I thought that they are in shape of the Gaussian function, but then I plotted the Gaussian function in GNU Octave and realized that Gaussian function doesn't have this kind of round top. I wonder what function was used to create the shape. Formula, anybody?

Surround and headphones

I bought a sound card with surround output. I don't really use any surround sound, but I often switch between speakers and headphones. I found a way to exploit the surround output. I connected the front stereo output to the speakers and connected my headphones to the surround output. I had to prepare a configuration file (I found examples in the Internet) that is saved in the "~/.asoundrc" file:

pcm.ch40dup {
    type route
    slave.pcm surround40
    slave.channels 4
    ttable.0.0 1
    ttable.1.1 1
    ttable.0.2 1
    ttable.1.3 1

pcm.!default {
        type plug
        slave.pcm "ch40dup"

pcm.dsp0 {
        type plug
        slave.pcm "ch40dup"

This ALSA configuration file routes duplicated output to front and surround out. Now I can use mixer to adjust volume for front (speakers) and surround (headphones) independently.

To make my life even easier I wrote a small script that switches between two sound profiles: speakers with music and headphones with microphone. I'm not publishing the script because it uses soundcard-specific control names. The script also turns the music player on and off. I created two icons on the system tray and linked them to the script.

My music background

This post is not about the background music for a blog. I personally hate background sounds for web pages and I believe you should never force the user to hear anything unrequested.

I decided to blog some information about my music background. I was involved in music for few years. Now I don’t deal with music any more. Here’s information about 4 bands that I’ve found and led:

  • Struktura – Jazz standards, swing songs and bossa-novas.
  • Hot Cargo – first funky music band
  • Funksters Jam Sessions – I’ve organized funky jam sessions in Warsaw. We played every Tuesday from 19:00 till 22:00. After few weeks the club was full every time we played. I even saw people recording our jams!
  • Funksters 1 – Consisted of people met on the jam sessions. We began with playing Brand New Heavies and Incognito covers.
  • Funksters 2 – Evolved from Funksters 1. This was a fully professional crew. See Funksters’ website, my first website ever. You can also download Funksters songs.

I have a pretty large collection of composition “stubs” which wait to be expanded. Sometimes I’m thinking about going back to music composition.

Music classification – Show me the music I’ll like

Imagine a plugin for your desktop music player. For each song, you set a flag, which indicates whether you like this song or not. It could be a very simple icon, like two faces: 🙂 and 😦 . The music player program learns from you and then tries to classify the newcoming songs according to your previous votes.

Why such a feature? Say, you're visiting a friend who has lots of music on his computer. His music taste will be somewhat different than yours. You're unable to manually browse a large collection of music. However, a trained filter would be able to quickly classify the music and find best matches from your friend's library.

What if because of this program I'll miss the most beatiful song in the world? – Well, you could have just missed it five minutes ago by not listening to some radio station or not buying some record in the music shop. Don't blame the technology.

Moving on with the topic – it is a concept similar to the spam filtering in email clients like Mozilla Thunderbird.

It is unclear now, whether the program should examine the whole file, or just some random parts. For a human being it is not uncommon to be able to assess the music from just few seconds of the music, for example when adjusting the frequency knob in radio, looking for a good station. Very often, just one second is enough to decide if you like this music or not.

One of the most important issues is to extract certain parameters from the sound file. The parameters should somehow follow the human perception of music. Personally, I think that one of the most important features of music is the ''sound'', by which I mean mostly the used instruments.

The features I can think of are:

  • Spectral flatness measure
  • Detect a beat and tempo (autocorrelation?)
  • Detect a set of instruments, maybe by frequency intensity in certain bands
  • Dynamics of the music (music volume changes)

I'm sure that during the development of the filter there would be new ideas about extractable features of music. As I know, MP3 format contains some already extracted features. I presume that OGG does as well.

Open source programs will be the best choice as it's possible to write extensions (plugins) for them. Personally, I can think of:

Beep media player (similar to Winamp, based on XMMS)

Rhythmbox (Gnome music management, inspired by iTunes)

See also:

Home music studio on Linux

Jack Audio Connection Kit + Hydrogen + Rosegarden + ZynAddSubFX + MIDI cable + new soundard with MIDI support for ALSA + (last but not least) Technics piano with MIDI out = Home studio! Did I miss anything? Oh yeah – Linux of course.

I tried the same thing about two years ago, but it was a failure. All applications were crashing very often, I got annoyed and gave up. Now it seems a lot different. Rosegarden crashed only once during today's session.

One of the quirks was the necessity of Jack recompilation. The jackd from SuSE 9.3 RPM package produced an "Illegal instruction" error. After recompiling it started working fine.

What's next? I think now I need to collect good-sounding instruments for ZynAddSubFX and try to install some LADSPA effects.