For the base logo design, I just took the logo they already had and simplified it a bit

Since cooler colors are more suited to be backgrounds, I made 2 variations with blue and purple. The logo itself is a black note with a white S to imitate a musical score where there are black notes on white paper

This is a variation only made because their original website has a maroon background

Here I made the S yellow/gold since it was the original color of their logo and then I reversed the note color to white and the background to black.

Update: After discussions with my client, he ended up wanting to have red and yellow in their logo because yellow is the original color of their logo and the red is the color of their street sign. In order to make the musical stand out a bit more with the red background, I made it white and that is the final logo.