The Driller Killer (1979) is director Abel Ferrara's first non-porno feature film. He stars as a struggling New York artist, Reno Miller, living with his girlfriend, Carol Slaughter (Carolyn Marz), and her girlfriend, Pamela Bergling (Baybi Day). One day a punk rock band, Tony Coca-Cola and the Roosters (not a real band) moves into the apartment next door, and they insist on rehearsing and partying all night every night, which starts to drive Reno insane. He purchases a cordless drill and starts murdering random people. It's a dark, arthouse film with lots of messed up comedy, very much representative of the New York punk scene of the time. Because the main character becomes a deranged killer, it's often lumped in with slasher movies.

It's public domain and available on Youtube (and elsewhere) for free: https://www.youtube.com/watch?v=AK9ABESU9FY