Prevent playback after stop() (#404)
Prevent playback after stop() (#404)

* Prevent playback after stop()

* add trailing period

Co-authored-by: Monica Dinculescu <47c73f713551e51cfc36b01f58a9583fe078c1b3@gmail.com>

magenta/magenta-js,magenta/magenta-js,magenta/magenta-js,magenta/magenta-js,magenta/magenta-js