This is specifically designed for people who want to program Atmega328P's to turn them into Arduino bootloader chips using an AVR-ISP sketch, but it can also be used to make a 'standalone' AVR ISP programmer - so that you can program blank chips without a computer!
Adding quality audio to an electronic project is surprisingly difficult. Here is a shield for Arduinos that solves this problem. It can play up to 22KHz, 12bit uncompressed audio files of any length. It's low cost, available as an easy-to-make kit.