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April 22, 2005
Footpedal...
When I perform saxophone and computer improvisations I can usually get most of the parameters that I want to control in the synthesis from my saxophone audio input. However, I can't seem to do without one pedal to control events in the larger time scale. This is something I am pretty confident I will be able to get rid of in due time. Even if it is just one single pedal it is annoying to have to keep pressing a pedal. It does take some of your focus away from playing. Also, on a conceptual level, I believe it bears some significance that interaction is solely based on what is being played on the instrument.
Until I have resolved this issue I will have to live with using a pedal which is in many cases also a technical problem. Either you can use a MIDI program change pedal which usually has five or more switches on it and is relatively large. Or you can use some kind of sustain pedal in which case you will have to connect it to some MIDI device. Either way you have to deal with MIDI which is something I want to avoid. After a suggestion was made to me by Miller Puckette I have now finally resolved this in a rediculously simple way.
By taking a standard on/off pedal switch and making a cable where the switch breaks the signal between two 1/4 inch jacks, connecting the two jacks to an input and an output of my audio interface and sending a sine wave through the output, I can measure the signal at the input and detect a pressed pedal. I made a simple Max/MSP patch that outputs a ‘bang’, a toggle or an incrementing index at each pedal press. Download the patch here. If you want to listen to some recent work for saxophone and computer follow this link.
Posted by henrikfr at 11:36 PM | Comments (0)
April 21, 2005
Real-time generation of musical material
In the saxophone quartet Persipicio I use real time analysis of what the saxophones play to generate and manipulate musical material and sounds. When I composed this piece in 2002 and 2003 I was under the impression that the fact that the analysis was done on the interpretation of the score rather than on the score itself was interesting enough in itself, not only on the analytical level but also on the level of perception. However, as I am revising the electronic part for this piece I am trying to address the question of significance. Why does a certain input give rise to a certain kind of output and what is the significance of this relation to the composition as a whole and to the events as such?
Another, more general question that may be asked is what is the limitations of the computer as an interactive performer and how should this limitation be dealt with in relation to the output of the computer and the whole? If we consider the analysis part of the specific computer program for this piece as the ears of the virtual performer how can we deal with the, on one level, restrictions these ‘ears’ have compared to human perception? Should I give up trying to implement or compose certain gestures and accept the restrictions or should I work with ways to circumvent them? And if I chose to do that how will that affect the real-time aspect of the composition?
Posted by henrikfr at 11:22 PM | Comments (0)
April 17, 2005
Perspicio - score following in Max/MSP
Two years ago Stockholm Saxophone Quartet premiered my piece Persicio for saxophone quartet and computer. I am very glad to have a second performance of it in two weeks - especially since the computer went down for the second part of the piece. For this piece I have implemented a basic score following that alligns the computer part with the saxophone quartet in order to avoid click track or pedals. As I am reworking the computer part (I don't want the computer to go down again...) I was astonished at how well the score following actually works.
I have used the same technique in another piece (Det Goda / Det Onda for flute and computer), but for Perspicio I had to deal with the fact that there are four instruments playing simultaneously, something which complicates the matter. The saxophones all have their own close range microphone and by employing some quite radical gating on all four inputs I have a fairly stable signal with output almost only when the respective instrument is playing. The computer only listens to one instrument at a time. In the score excerpt (the score is transposed - Eb alto, Bb tenor, Eb baritone, Bb bass) the cue notes are marked with a horizontal arrow.
The technique is quite simple. I chose a window of a few beats up to a few bars in which I look for a discrete pitch or pattern that only occurs once within this window and I set the computer to wait for this pitch. Once it is found the window is moved forward in the score and the computer is waiting for the next pitch. Obviously, between the first cue note and the second cue note the second pitch to look for must not occur until the actual cue. Some attention has to paid to what the other parts are playing since, although the signals are gated some over hearing may occur and result in a ‘false’ trigger. In some sections I have to ‘mute’ the input signal altogether for a few seconds in between cues in order to avoid dubbel triggering.
The computer part is done in Max/MSP and I am using Ted Apel's port of Miller Puckette's fiddle~ object which works well for what I need. In the new version I had some trouble with getting Puckette's qlist object working so I ended up doing my own adaption of it (read bout that here). For each cue I have also entered a ‘time out’ value - if the note was not found in within this time frame the system will cue itself and start looking for the next cue note. By calculating the time between the cues and compare this to the intended time according to the score, I can extract relevant tempo information that will adjust the time out values but also adjust the timing of events in the compter part.
For basic performer-computer temporal alignment I can recomend this method. It does have flaws, but the great advantage is the low computation cost and the stability. As soon as I have finished the reworking of the patch I will upload the whole thing here.
Posted by henrikfr at 09:33 AM | Comments (0)
April 16, 2005
Max implementation of qlist
After having problems with the adaption for Max of Miller Puckette's qlist object I finally decided to implement the basic idea of qlist in an abstraction using the standard library coll object. The idea is to have a list of cues where each cue contains a set of messages to be sent at the time the cue was received or at a specified time. The syntax for writing the text file to load into the collist object is simple and very similar to the syntax for qlist. Here is an example:
0, ------------------------ 1;
1, 0 print *** this is a message from collist ***;
2, print cue 1;
3, 2200 strt_spl 4 1;
4, ------------------------ 2;
5, 0 print *** this is a message from collist ***;
6, print cue 2;
7, pt_vce_ctrl 2;
8, 500 strt_spl 4 1;
9, ------------------------ 3;
On cue 1
collist will print “*** this is a message from collist ***” and “cue 1” in the Max window and 2200 ms later it will send the list 4 1 to the receive object named strt_spl.
The object takes one argument - the name of the text file to be read. This is just an abstraction so doubleclicking on the object will open a patcher window where there is a readme subpatcher with documentation. One thing that is good to know is that although the lines in the collfile may be numbered consecutively, you can always insert new rows anywhere and send the renumber message to the rightmost inlet of the collist object. For example, if you want to insert a message between lines 3 and 4 in the example above just write:
0, ------------------------ 1;
1, 0 print *** this is a message from collist ***;
2, print cue 1;
3, 2200 strt_spl 4 1;
31, do_this 1;
4, ------------------------ 2;
...
and than send the
renumber message and the rows will be nicely renumbered consecutivelyI also wrote a little Perl script that changes a original qlist file to the collsyntax. It needs some cleaning up, but feel free to send me an email if you want it and maybe I can get my act together and make nice and tidy. Download the object from here but remember, although it works for me, I can in no way garantee that it will work for you but feel free to use it and change it as you wish.
Posted by henrikfr at 01:05 AM | Comments (0)
April 15, 2005
California - travel log (2)
At UC Santa Barbara the department for research in the field of electronic art is called CREATE. Author of the great book ‘Microsound’ Curtis Roads is Associate Professor and Stephen Travis Pope is their Senior Research Specialist. The Director is composer JoAnn Kuchera-Morin, one of the few women in this field. A new building that will host CREATE is opening next year. It will feature a data visualisation space - a sphere with 127 speakers and a 360 degree projection surface and 3D imagery. Imagine being inside a giant football... There seems to be a well developed interaction between the Media Arts and the Technology departments at the University and the new building and its spaces will be shared with researchers from the natural sciences (nanotechnology, biotechnology etc). This is something that we at Lund University still are having problems achieving, partly because of the geographical distance between the departments. Personally I don't think there is a lack of interest, just a lack of initiative. Hopefully, my collaboration with the department of Theoretical Physics is a beginning that can lead to a further expansion of crossdisciplinary interactions and collaborations.
At CNMAT, Berkeley, I met with some of the graduate students at the composition department. One of them, Brian Kane I met at the Spark Festival in Minneapolis in January. Not only is he a remarkable intellectual and a great composer with a background in philosophy, he is also a highly skilled jazz guitarist. At Spark he delivered a paper on phenomenology and Pierre Schaeffer that was noteworthy. As problematic as Schaeffers theories can be, there is still a lot of his work that is applicable today. I sat in on an informal seminar where the grad students in composition got together and discussed their recent work. I was envious of the way in which the students evidently self organised and initiated discussions such as the one I was part of considering how little interaction there actually is in our own PhD program.
In San Diego I also played a gig at the Gallery Voz Alta, arranged by the Trummerflora Collective. There seems to be a fairly active experimental music scene also outside of the University. I met Hans Fjellestad who helped set up the concert, a great musician and keyboard/pianoplayer filmmaker. I haven't seen his filmwork but his CD 33 is deeply original. At the concert flute and reedplayer Ellen Weller sat in on the second set. Check out her CD ‘Spirits, Little Dreams and Improvisations’ on Circumvention Music where especially the free stuff is great.
Posted by henrikfr at 11:01 PM | Comments (0)
April 14, 2005
California - travel log
I have just spent two weeks in California, playing concerts and meeting musicians and composers. I visited four computer music departments at four universities: CRCA at UCSD, CREATE at UCSB, CNMAT at UC Berkeley and CCRMA at Stanford. There is an incredible activity at all of these places - three of them are opening new facilities within the next year. This is especially interesting considering our local InterArts Center here in Malmö. These places are, as far as I understand, related to but independent from the respective music departments. When talking to the people involved in the development and managment I gathered that the need for an independent organisation came from the incompatibility of conservatory traditions with new music and new media. I find this thoughtful in more than one way and maybe it is the only solution to the problems involved when bringing cross disciplinary activities such as computer music and interactive media into the context of traditional music education.
UCSD has a critical studies program (Critical Studies and Experimental Practices in Music) with many interesting graduate students. This program seems to have many similarities with the artistic research program that I'm part of myself - both on the level of the student experience and the organisational ambition (with some reservations on my part - I really haven't checked it out thouroughly). I met with Nina Eidsheim whose quartet soNu I already knew about through Danish saxplayer Marten Carlsen, and through her I met another voice artist, Chris Tonelli and Tildy Bayar, a flutist. Arshia Cont is an interesting Iranian composer and grad student in computer music.
I also met with Miller Puckette and sat in on one of his research seminars. I am hoping to be able to spend some more time at CRCA in the future and work more closely with Puckette. He is one extraordinary mind and I believe he can be of great help to me in some of the phases of my project. Unfortunately I missed Mark Dresser who is a new faculty member but I am hoping to be able to hook up with him at a later stage being the great improvisor that he is.
At CCRMA Chryssie Nanou is a pianist specialising in performance of piano/computer music doing a visiting researcher residence. Here I also met a Ph.D. student, Hiroko Terasawa, doing similar work to my own timbre recognition. At CCRMA students and researchers with many different backgrounds come in and do work related to the performance, realisation or creation of computer mediated music. Although my visit was brief, i was impressed with the multi dimensionality of the work I encountered there. I am hoping to be able to spend more time there as well some time in the future.
I will write more about CNMAT and CREATE in my next post.
Posted by henrikfr at 08:09 PM | Comments (0)