What are you expecting delay to sound like ?
EDIT: The delay is added to the output, so if you can hear the output, and bDelay = true; the delay is there.
As the Auduino outputs at a constant volume the delay can be heard as a reverb effect.
In projects with an attack/decay or even just on/off notes, the delay is more obvious as a repeat or echo of the initial note -
The same delay code running on the five dollar keyboard -
Duane B