I made a quiz that prompts you with a given note. If you play the right note, you get the next question. It requires you to have a microphone (built-in on the laptop works), an instrument, and for bass, probably an amp of some kind. http://www.tamphan.com/playthenote/ It only works on Chrome for desktop or android. I tested it on Chrome for iPad and it doesn't seem to work. The tuner isn't the greatest, so it sometimes has issues recognizing notes. F#/Gb seems to be an issue. Usually playing the same note but in a different octave will get you to the next question if you're getting stuck. I've tested it with a precision bass with an amp sim and speakers and my laptop seems to recognize the notes ok. I've also tested it with an acoustic guitar. Thanks for any feedback you might have!