Michael Lohan -- The Pre-Arrest Karaoke Sesh [VIDEO]

Hours before Michael Lohan was re-arrested in Tampa last night for allegedly harassing his GF Kate Major, the man got real loose at his hotel bar -- belting out "American Pie" on the karaoke machine -- and the video is hilarious.

As we first reported, MiLo was arrested at the hotel soon after -- but not before allegedly trying to flee from cops by hopping his 3rd floor balcony ... and plummeting 34 feet to the ground.