Originals: Back in Your Life by Jonathan Richman (covered by Galaxie 500)
Argh! Didn't think this was going to be a tricky one... looks like UMG are busy wandering around YouTube asserting their rights to (taking down!) the Jonathan Richman and The Modern Lovers LP Back In Your Life - as I don't particularly want to incur the wrath of the major labels (again) the best I can offer is...
For Spotify users...
This "Swell Tunes" Tumblr also has the song.
Back in Your Life was a cover that Galaxie 500 certainly played at least once in their early days - we know this because it turned up on the rather excellent "Don't Let Our Youth Go to Waste" as part of the set they played at The Middle East in Cambridge, MA on March 19th 1988.
Here's the video, watch the whole set or jump to 7'45" in to get to the cover of Back in Your Life