I find a lot of songs refuse to play at all, or cut out halfway through.
You need to flag the song by doing the following:
- Hover your mouse over the song until you see the options menu come up.
- The options menu is represented by a "+" with a down arrow next to it.
Click the gear, choose the "Flag Song" option and select what is wrong with the song from the menu.
You should flag a song if it will not play, skips, is low-quality, mislabeled, contains explicit lyrics, or has the wrong album art.