Add currently playing song to playlist

If you are listening to a song and start a new search in the meantime (you may have not yet decided if you are happy with the currently playing song), there is no obvious button to then add the currently playing song to your playlist. Right now, one has to search the song again, and look through/listen to the results again, since there's no way to know which particular song version you were listening to... a link for this could be added to the currently playing box and go alongside Buy Song, etcetera.

Edit: Okay, so I see if one thinks to click on the currently playing song title, this ability is hiding there... maybe it should be a bit more obvious?