(activity pos dur sprog sarg eprog earg)

Returns a new activity with position pos, duration dur, start program sprog, start arguments sarg, stop program eprog, and stop arguments earg. The position can be any type, the duration should be a number. The arguments sarg and earg should be arrays (see list->array).

(set-position! a pos)

Sets the position of activity a to pos. This modification may induce a reorganization of the musical structure in which a is included. This reorganization may fail and result in an error. In that case the original position of a is retained and no changes are made to the original structure.

(get-position a)

Returns the position of activity a.

(set-duration! a dur)

Sets the duration of activity a to dur. This modification may induce a reorganization of the musical structure. If the reorganization fails, the original duration of a is kept and no changes are made to the structure.

(get-duration a)

Returns the duration of activity a.

(stretch a f)

Stretches the duration of activity a by a factor f. See also set-duration!. This is short for (set-duration! a (* (get-duration a) f))

(get-start-prog a)

Returns the start program of activity a.

(get-start-arguments a)

Returns the start arguments of activity a as an array.

(get-stop-prog a)

Returns the stop program of activity a.

(get-stop-arguments a)

Returns the stop arguments of activity a as an array.

(set-start-prog! a prog)

Sets the start program of activity a to prog.

(set-start-arguments! a arg)

Sets the start arguments of activity a. arg should be an array.

(set-stop-prog! a prog)

Sets the stop program of activity a to prog.

(set-stop-arguments! a arg)

Sets the stop arguments of activity a. arg should be an array.

(get-pattern a)

Returns a reference to the pattern in which activity a is included.

(play a)

Plays the activity a.

(new-sound-activity pos dur voice num)

Creates a new sound activity with position pos, duration dur, synthesis voice voice, and num number of voice arguments.

(sound-activity pos dur voice freq amp a1 a2 ...)

The procedure sound-activity creates and initializes a sound activity. The arguments freq and amp are control functions indicating the frequency and amplitude evolution of the sound activity. a1, a2, ... are additional arguments for the synthesis voice.

(sound-activity-set-arg! a v i)

Set the i-th argument of the synthesis voice of sound activity a to v.

(set-freq! a freq)

Set the frequency control function of sound activity a to freq.

(set-amp! obj amp)

Set the amplitude control function of sound activity a to amp.

(note dur v mc db)

Creates a new note object with duration dur, pitch mc (in midi-cents), and intensity db (in decibels). The note will be played using the synthesis voice v.

(set-pitch! n mc)

Set the pitch of the note n to mc (in midi-cents).

(set-intensity! n db)

Set the intensity of the note n to db (in decibels).

(chord dur v mc-list db-list)

Creates a new chord object with duration dur, pitches mc-list (in midi-cents), and intensities db-list (in decibels). The chord will be played using the synthesis voice v.

(rest dur)

Creates a new rest object of duration dur.