Record three prototypes: 'a', 'b', 'c', and save the prototype file as "-mi.MyFile". Now go back to the main dialog (see Fig.2). The "Play object alone" button is similar to the one you have already used, except that it allows you to try dilation ratios -- a good way of determining acceptable ranges.

Type "abcbaa" in replacement of "[Any expression]" and click "Play expression:". You hear the musical item notated "abcbaa". The corresponding graphic score is displayed on the "Graphic" window if "Show graphic" is checked on the "Settings" dialog (accessed by typing cmd-option space). If you modify pivot positions for 'a' you will quickly figure out pivots. Changing the metronome value will also demonstrate dilation and contraction within the limits that have been specified.

Make prototype 'a' longer than one second and play the expression with mm = 60. The end of 'a' will overlap the beginning of the first occurrence of 'b'. Then set property "Never cover beginning" for 'b' and play the same expression. You will notice that 'b' has been delayed by just the right quantity to prevent overlapping, as shown in Fig.4. This has been achieved by the time setting algorithm.

Now, declare that 'b' should not be relocated. (Click "Duration/pivot/location" to display this property.) Did you notice that the pivot of 'b' has become a complete arrow? Click again "Play expression". The time setting algorithm will try to "break the tempo" on 'a', thereby meaning that the metronome stops counting until 'a' is over. (This is called organum in Western music.) Note the delay on time streaks (the blue vertical lines) on Fig.5.

If you further declare that 'a' should never break tempo, the solution will be that the first 'a' is shifted to the left (forwarded)... Try more! In the end, if 'a' is also not relocatable, no solution will be found: BP2 will take your permission to ignore constraints and produce a score identical to the initial one.

You may refer to §5 of the reference manual for details about the time setting of sound-objects which was demonstrated here. An example is provided with "-da.checkTimeSet". (Load the file to the "Data" window. This will also load settings "-se.checkTimeSet" which force the time setting process to be displayed.) Display options may be changed by typing cmd-option space or selecting "Settings" in the "Windows" menu.