Here's another great idea from the Swap-bot site... it is not only mail art, but this time the idea is to illustrate the lyrics of a song.
Above is the envelope I sent to Canada. I choose La Vie en Rose (sang by Edith Piaf in French and made famous by Louis Armstrong in the States
This is the envelope I got all the way from Australia. It illustrates a song called Beware of Young Girls by Doris Previn. I never heard of it, but I was charmed by the young girls that illustrate it. Thank you to my swap-bot partner: Aleisha!