[wztvzqly] Rhythmic code

Create a rhythmic code, like Morse code, but for which each letter takes exactly the same amount of time.  Then, the code can be "played" in time to a constant time signature, e.g., 4/4 common time.

First attempt: the code consists of eighth notes (and eighth rests) occupying the first 3 counts of a common time measure.  The last beat is always a quarter rest to aid synchronization.  There is always a note on the first beat as well.  This leaves 5 positions which can be a note or rest, for 32 possibilities.  However, many of these rhythms will be heavily syncopated, which is perhaps not so good when needing to precisely recognize rhythms.

Second attempt: message measures alternate with synchronization measures. The synchronization rhythm is two quarters and a half note. On each beat of a message bar can be a quarter or two eighths, for a total of 16 possibilities: hexadecimal. Played in cut time.

3 measures of message, then a complete (and distinctive) synchronization measure, for an 8 bar phrase.