So today I wrote the following AppleScript that I then placed in the iTunes script folder (~/Library » iTunes » Scripts), which makes it accessible from the script menu in iTunes:
tell application "iTunes"
set currentTrack to current track
set playPosition to player position
set theSampleTrack to selection
play selection
set player position to 50
display dialog "Sampling Track. Click Stop to revert to the previously playing track" buttons {"Stop"}
if button returned of the result is "Stop" then
play currentTrack
set player position to playPosition
end if
end tellIf I come across a song I'd like to hear a little bit of, I select my script from the menu (I've saved mine as Sample this song). It then starts to play the selected song and displays a dialog box with a stop button. When I have heard enough, I hit the stop button and the song that was previously playing begins again from the position at which I interrupted it.
In the script, I have included the line set player position to 50. This starts playing the selected song from 50 seconds in to avoid listening to lengthy intros. This can be amended or deleted if you'd prefer to sample the song from the beginning.

