Dotted eighth note:

Take the song tempo in beats/minute (BPM).

Do some math:   60/BPM=Time per beat ; Time per beat X 1000 = Time per beat in milliseconds

A dotted eighth note is 3/4 of a beat ( 0.75 of a beat).

Do some more math:  Time per beat in milliseconds / 0.75 = your delay setting for that song at that temp repeating a dotted eighth note.

EXAMPLE:

Set a delay for dotted eighth note delay time in milliseconds for a song with a tempo of 100 beats per minute:

60 / 100 = 0.6     (time per beat in seconds)

0.6 X 1000 = 600  (time per beat in milliseconds)

600 X 0.75 = 450 (delay setting in milliseconds for a dotted eighth note delay at 100 beats per minute.

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2.311 Hz

Hz (Hertz) indicates how many times something happens in one second.

There are 1000 milliseconds in a second.

To get a delay setting in milliseconds when given hertz, you simply do the math:

1000 / Hz = delay setting in milliseconds.  (actually the reciprocal of the frequency)

EXAMPLE:

Set a delay in milliseconds to repeat at a frequency of 2.311 Hz.

1000 / 2.311 = 432.71  (your delay setting in milliseconds, but you should probably round off to 432 ms or even 430 ms.)

Conversion factors:

Where we used .75 for a dotted eighth note, here are the figures you use for other common note values:

Whole Note                      4

Dotted Half Note             3

Half Note                          2

Dotted Quarter Note      1.5

Quarter Note                   1

Dotted Eighth Note          0.75

Eighth Note                       0.5    

Dotted Sixteenth Note     0.375

Sixteenth Note                  0.25

Hope this helps,

Joe