SASL is part of MPEG-4 Structured Audio . It has to do nothing at all with the subject of this page (music notation, visual rendering...). I just spent some time looking at it because its name implies some relationship with music notation.
But if you're thinking of events instead of slurs, chords, augmentation dots, bars... when you hear the word "score", SASL might be exactly what you want. Here are some developer resources for you.
Feedback (questions, suggestions, broken links): SASL: Simple Audio Score Language
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