Hi Fons! Mar 6 2022, Fons Adriaensen has written: ... There is the release opcode, triggered, when an instrument is in its last control cycle (k-cycle): if (release() == 1) then ; last action, i.e.: schedulek(86, 0, iDuration) endif This should work. I am not completely sure about release. Some actions it won't can't perform. But, when the duration of the instrument is known, set before, then there are other options. This can only be done, if the instrument is not played live from MIDi or something. instr 85 ; Set the duration: if (p3 < giDur) then ; make sure it lasts at least giDur seconds xtratim(giDur - p3) ; add the extra amount endif ; Make sure instr 86 is played, when this instrument event ends schedule(86, giDur, iSomeDuration) ... endin schedule should only be triggered at init time, i.e. when the current event is started. The schedulek version should be triggered, whenever it is needed, i.e. based on some runtime condition. There are more "realtime" aspects to schedulek which can be used. ... ... I think this should fail because of two things: I think the + (increased time counter) is related to instruments, so 85 would take the values from 84. Not sure though. One second is a long duration, unless the duration is expected to be longer this might fail. I am not 100% sure about p3/duration handling. But I think you can extend the duration with xtratim or a release envelope, but not shorten it. Lastly, no scheduling is given to instrument 86. This is best done in the score. Yet another way, if the given structure is best suited, used instrument 84 as a "main program": instr 84 iDelay = filelen($INPFILE) schedule(85, 0, iDelay) ; you can add more parameters schedule(86, iDelay, iSometime) ; again more parameters are possible endin This will perform the action once. Instrument 84 does not need to run for long. You can even add this as the last line: turnoff This will terminate the instrument, once those calculations and actions are taken. You can slim it down, by having the processing of the input in instrument 84 as well, unless even instrument 85 should be started with a delay, because of other preparation work. Sorry, for the long mail. Every single option is viable, depending on needs, style and structure, one may suite better than another. I'm sure there are even more solutions, depending on the context. Should multiple files be processed, should there be repitition, etc. HTH. Best wishes, Jeanette -- * Website: http://juliencoder.de - for summer is a state of sound * Youtube: https://www.youtube.com/channel/UCMS4rfGrTwz8W7jhC1Jnv7g * Audiobombs: https://www.audiobombs.com/users/jeanette_c * GitHub: https://github.com/jeanette-c Our imagination Taking us to places We have never been before... <3 (Britney Spears)