If you really need to be heard above the crowd, connect the Blues Playground to a guitar amplifier. The simplest way to connect the two is with a pair of alligator clips and a 1/4" guitar signal cable.
The guitar amplifier needs two connections, one as a common ground and the other for the musical signal. Clip a black alligator wire lead to the GND connection of the CPX. An alligator wire of a different color is clipped to the ~A0 (analog signal output) pin. Remember the screws we attached earlier? The clips will hold well to those.
The other ends of the alligator clip wires attach to the Tip and Shield of the guitar cable plug. If your alligator clips are large enough, you can attach directly to the plug. If not, unscrew the plug handle and attach directly to the pins of the plug where the guitar cable wires are soldered.
Turn the amplifier's volume all the way down before turning on its power. The CPX puts out a loud signal!
If you encounter hum when no sound is playing, you may not have a good connection or your alligator clip wires are too long. Short lengths will reduce the antenna effect of the unshielded wires.
Do you want to play the blues in a minor key? If you're handy at recording your own chord samples, put the new sound files in a compatible format, store them on the CPX, and update the CircuitPython code to show the new chord file names. Mike Barela wrote an excellent guide that can help with the sound file conversions: Microcontroller Compatible Audio File Conversion.
For more information about the origin of the blues musical genre, try https://en.wikipedia.org/wiki/Blues. Examples of blues songs can easily be found on YouTube and most recorded music catalogs.