First recorded (as a demo) by Pete Townshend (1978).
Hit version by The Who (US #14/UK #18 1978).
From the wiki: “‘Who Are You’ was written by Pete Townshend and which became the title-track of The Who’s 1978 album, Who Are You, the last album released before drummer Keith Moon’s death in September 1978. According to Townshend, the inspiration for the song began with a very long, excruciating meeting in New York City regarding royalties for his songs (the reference to ‘Tin Pan Alley’ in the song). After the meeting, he received a large check for royalties, left and went to a bar and got completely drunk. In that bar he encountered Paul Cook and Steve Jones of The Sex Pistols, who thought very highly of Pete for paving the way for Punk rock music.
“Townshend was conflicted because he feared The Who had sold out, and seeing The Sex Pistols, who were icons of rebellion, exasperated him even more. Pete left that bar and passed out in a random doorway in Soho (a part of New York). A policeman recognized him (‘A policeman knew my name’) and being kind, woke him and and told him, ‘You can go sleep at home tonight (instead of a jail cell), if you can get up and walk away.’ Pete’s response: ‘Who the f–k are you?’
“Townshend has only vague memories of writing this song, as he composed it with a hangover. He explained: ‘I’d like to think that where the song came from wasn’t the feet that I was drunk when I did the demo, but the fact that I was f–king angry with [manager] Allen Klein, and that the song was an outlet for that anger.’ According to Townshend, the song came out different than intended when Roger Daltrey sang it. Townshend said the song as originally intended was a prayer from a destitute man. The man is on the street, looking up to the sky and asking God, ‘Who are you?’
“The Who’s Roger Daltrey recalls: ‘We were getting incredible accolades from some of the new Punk bands. They were saying how much they loved The Who, that we were the only band they’d leave alive after they’d taken out the rest of the establishment! But I felt very threatened by the Punk thing at first. To me it was like, ‘Well, they think they’re f—ing tough, but we’re f—ing tougher.’ It unsettled me in my vocals. When I listen back to ‘Who Are You?’ I can hear that it made me incredibly aggressive. But that’s what that song was about. Being pissed and aggressive and a c—!'”
The Who, “Who Are You” album version (1978):
The Who, “Who Are You” alternative take from The Kids Are Alright (1978):