Bass pattern offset 2+81?

[smrz]

The 'Swing' groove (file swing.mma in stdlib) defines bass patterns

Begin Bass Define
   Sync1   1 4  1 90; 2+81 16 1 80; 3 4 1 90; 4+81 16 1 80
   Sync2   1 4  1 90; 2+81 16 1 80; 3 4 5 90; 4 4 1 80
End

This includes the offsets "2+81" and "4+81".  What do the "+81"s do to the offset?

According to mma documentation,

         "The note offset can be modified by appending a single or multiple set of “+” or “-” signs. Each “+”
         will force the note up an octave ..."

The documentation doesn't say anything about <offset>+<a number>.  Adding the +81 changes the pattern's sound, but I can't figure out what it's doing.  Any thoughts would be appreciated.

Thanks

[bvdp]

From the docs in the section "Patterns":

The offset can be further modified by appending a note length (see the duration chart, below). If you want to specify an offset in the middle of the first beat you can use “1.5” or “1+8”. The latter means the first beat plus the value of an eight note. This notation is quite useful when generating “swing” sequences. For example, two “swing eights” chords on beat one would be notated as: “1 81 90; 1+81 82 90”.

Just a few lines down from this the different note durations are listed. So, in your example you have "2+81" which simply means that the start point for that event is beat 2 PLUS the duration of the "first pair of a swing eights".

You are reading the section for "Bass" notes which takes liberties by not repeating the first section which gives the overall specs for the offset, duration, etc. You are also confusing "note offset" with "position". The NOTE OFFSET is the actual pitch to pick from the underlying scale for the current chord. The + and - referred to in the Bass section change the octave of the note/pitch.

Hope it's all clear now. Shout if not!

[smrz]

I can't believe I didn't see the chart.  Thanks!

[bvdp]

I'm convinced that the manual for MMA is too large But, then so is MMA