Hi, I'm very new to Arduino, Processing and coding in general. I'm building a little drum machine, so I'm trying to get these buttons to play mp3 files on my computer, but the only help I could find so far was an explanation on how to do it if I were to have an external speaker hooked up to the Arduino - I need to use the computer's internal speakers. All help would be greatly appreciated!! Sorry if this has already been explained in another post
The Arduino can read the switches, and send serial data to the PC. If the serial data consists of messages like "Hey, you ancient pile of junk, play the third song now", then a Processing application could read that serial data, and play the third song.
Of course, you are free to send serial data that is more easily parsed.