Depends who the friend was. If they had no music whatsoever, I'd laugh at them and then give them the following bands:
- The Beatles
- Green Day
- Blink 182
- Fall Out Boy
- Queen
Mainly just to see what they'd take to. Once they've voiced their particular attachment to one or more, I'd recommend some of the following:
- Paramore
- Panic at the Disco
- My Chemical Romance
- Did I mention The Beatles? Oh, moar of them then.
- The All-American Rejects
- Sum 41
Then from there, I'd recommend more! But we won't go there.
As for songs I'd recommend:
- the entire Beatles catalogue. This is not a joke.
- "Holiday" by Green Day
- "Saturday" by Fall Out Boy
- "Mad as Rabbits" by Panic at the Disco
- "Almost Lover" by A Fine Frenzy
- "Seven Wonders" by Fleetwood Mac
- "Roses for the Dead" by Funderal for a Friend
- "Iris" by the Goo Goo Dolls
- "The Remedy" by Jason Mraz
- "IMAGINE" by John Lennon [c'mon, this is an essential]
- "My Heart" by Paramore
- "Angel" by Sarah McLachlan
- "Pieces" by Sum 41
- "Angels on the Moon" by Thriving Ivory
Yeah, I could go on for a long time. I think I may make some playlists, soon actually. Themed playlists. YES. Enjoy the new songs if you haven't heard of any of them. GET THE BEATLES WHOLE ENTIRE CATALOGUE.