Re: What music would Patrick Bateman listen too?
As much as you're trying to stick with the film's soundtrack, you may want to consider the books of Bret Easton Ellis (namely "Less Than Zero", "The Rules of Attraction" and the novel of "American Psycho"). I know in the novel of "The Rules of Attraction", I remember there being a reference to "Dancing With Myself" by Billy Idol. I'll check around to see if there's any other references to other songs in his other books and post then here (you could even use the Elvis Costello songs that inspired the titles of "Less Than Zero" and "Imperial Bedrooms.")
Update:
Songs from the novel "Less Than Zero":
“New Kid In Town” — The Eagles
“Crimson & Clover” — Joan Jett & The Blackhearts
“In The Sun” — Blondie
“I Love L.A.” — Randy Newman
“Hungry Like A Wolf” — Duran Duran
“Somebody Got Murdered” — The Clash
“Do You Really Want To Hurt Me?” — Culture Club
“Straight Into Darkness” — Tom Petty and the Heartbreakers
“LA Woman” — The Doors
“Los Angeles” — X
“Earthquake Song” — The Little Girls
“Sex and Dying in High Society” — X
“Stairway to Heaven” — Led Zeppelin
“Less Than Zero” –- Elvis Costello
“Song For Clay” — Bloc Party
Songs from the novel "The Rules of Attraction"
“Burning Down The House” — Talking Heads
“Walk Away Renée” — The Left Banke
“Revolution” — Thompson Twins
“Every Breath You Take” — The Police
“Town Called Malice” — The Jam
“The Message” — Grandmaster Flash
“Funeral for a Friend” — Elton John
“Dancing With Myself” — Billy Idol
“Your Silent Face” — New Order
“The Boys Of Summer” — Don Henley
“The Unforgettable Fire” — U2
“Venus in Furs” — The Velvet Underground
“The Weakness in Me” — Joan Armatrading
“William, It Was Really Nothing” — The Smiths
“Love Of The Common People” — Paul Young
“Unsatisfied” — The Replacements
“Ashes To Ashes” — David Bowie
“And She Was” — Talking Heads
“Born In The USA” — Bruce Springsteen
“Love Will Tear Us Apart” — Joy Division
Songs from the novel "American Psycho" (includes some from the film)
“Hip to be Square” — Huey Lewis & The News
“New Sensation” — INXS
“Faith” — George Michael
“The Confrontation” — Les Misérables (Original London Cast)
“Love is a Contact Sport” — Whitney Houston
“Anything She Does” — Genesis
“Jacob’s Ladder” — Huey Lewis & The News
“Party All the Time” — Eddie Murphy
“I Feel Free” — Belinda Carlisle
“Brilliant Disguise” — Bruce Springsteen
“Devil Inside” — INXS
“Greatest Love Of All” — Whitney Houston
“The Heart Of Rock & Roll” — Huey Lewis & The News
“Sussudio” — Phil Collins
“In Too Deep” — Genesis
“I Wanna Dance With Somebody” — Whitney Houston
“Like A Prayer” — Madonna
“I Want A New Drug” — Huey Lewis & The News
“Follow You Follow Me” — Genesis
“Heaven Is A Place On Earth” — Belinda Carlisle
Songs from "The Informers"
“Church Of The Poisoned Mind” — Culture Club
“Zig Zag Wanderer” — Captain Beefheart
“Suddenly Last Summer” — The Motels
“Head Over Heels” — The Go–Gos
“Jessie’s Girl” — Rick Springfield
“Our Lips Are Sealed” — Fun Boy Three
“Peaceful Easy Feeling” — The Eagles
“Oldest Story in the World” — The Plimsouls
“It Had to Be You” — Tony Bennett
“Material Girl” — Madonna
“Everybody Have Fun Tonight” — Wang Chung
“Do You Wanna Touch Me (Oh Yeah)” — Joan Jett
“Destination Unknown” — Missing Persons
“Beautiful World” — Devo
“A Million Miles Away” — The Plimsouls
“Jeopardy” — Greg Kihn
“Love Her Madly” — The Doors
The Petticoat Junction Theme Song
Songs from "Lunar Park"
“Everyday I Write The Book” — Elvis Costello
“Witchy Woman” — The Eagles
“Thriller” — Michael Jackson
“Rhiannon” — Fleetwood Mac
“The Monster Mash” — Boris Puckett and The Cryptkickers
“Pet Sematary”– Ramones
“Evil Woman” — ELO
“Werewolves of London” — Warren Zevon
“Creep” — Radiohead
“Glory Days” — Bruce Springsteen
“London Calling” — The Clash
“Time of the Season” — The Zombies
“Feels Like the First Time” — Foreigner
“On the Sunny Side of the Street” — Tony Bennett and Willie Nelson
“You’re Beautiful” — Kenny G
“Funeral for a Friend/Love Lies Bleeding” — Elton John
“Someone Saved My Life Tonight” — Elton John
“One of These Nights” — The Eagles
“Life’s Been Good” — Joe Walsh
Song Lists from:
A Musical Overview of Bret Easton Ellis’ Oeuvre – Flavorwire
As for what Bateman would listen to, I'd recommend just using some of the list for the novel.