*NOTE* Shazam has updated it's app and this no longer works for shazam. A fix is not planned. Sound Search for DashClock is an extension for DashClock Widget.
Quickly search for the song you are currently hearing using this extension for DashClock.
Google Sound Search (have to manually select music mode)
SoundHound and SoundHound ∞
Shazam and Shazam Encore
Sound Search for DashClock requires DashClock Widget by Roman Nurik: