Note the title and singer of each song you hear.
Once you have 5 songs noted, make a plot about the titles, the meanings, the ones singing, or all/some of these, then write a fic.
For example... I put my iPod on shuffle. The songs I get are:
1. Megurine Luka - Just be Friends
2. Kamui Gakupo - Joker
3. Gumi - Poker Face
4. Hatsune Miku - Toosenbo
5. Kagamine Len - Tururiratariraturura
Then, I think of a plot.
Then, I write a fic using the plot I just came up with.
1. Don't skip songs! If the 5 songs you got can't make a plot no matter how much you think, either write a crackfic or start again.
2. Have fun!