have been melting my head on ae expressions all night trying to get something that will "move to the beat"

Math.sin(time*7);

is about right it seems, and then you mulitply that by what ever you need the unilt to be, ie if you want a solid to flash to the beat, stick that expresion on its opacity with an extra times 100 on the end:

Math.sin(time*7)*100;

Thanks to Mr Gifford and Mr Ebbert for their helpful sites...

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