Since we just do string interpolation for what we pass as pitch and duration to sonic pi, we should put the eval statement in the speedy eval loop in a begin rescue so that it just fails fast and doesn't break the listener.
I apparently already do this, so I am closing this, but I don't know yet why when we put a weird symbol in the string field of the play synth block it broke for Catherine.
Since we just do string interpolation for what we pass as pitch and duration to sonic pi, we should put the eval statement in the speedy eval loop in a begin rescue so that it just fails fast and doesn't break the listener.