Hi, I extended the chuck source code with a new unit generator what can be used to play sound samples in a way what is somewhat similar to "tracker" software like renoise, fast tracker, buzz etc. There is a concept of "samples", "instruments" and "tracks". A "sample" is a sound sample, an "instrument" adds new parameters to samples like loop points and a base frequency. A "track" is a chuck unit generator which can play back the "instruments" mentioned before, and it can be thought of as a column of a pattern in a pattern sequencer software. The main feature is that the track ugen has support for volume and frequency modulation, slides and sample retrigger effects, and each of these is computed for every sample. (So the control rate is the sampling frequency of the dac.) The volume and frequency of a sound sample can be modulated by any other sample. Note that this all could be written in chuck itself, but I chose to write it as an ugen to have better efficiency, because I like to make sounds this way. I think the system provides more or less the same functionality as the LiSa ugen, but the track concept allows even more interesting possibilities. To make it clear: This is already written and (more or less) tested by myself! So if there is general interest in such a new ugen I am happy to share this work with the public. (In my opinion it is somewhat special, but some people might find it useful.) Note that for testing one has to compile ChucK from the source code with a patch.. Imre