The song is a parody of "Piano Man" by Billy Joel released in 1973. The original song contains the chorus "Sing us a song. / You're the piano man. / Sing us a song, tonight. / Well, we're all in the mood for a melody, / and you've got us feeling alright"
That is not a Weird Al song.
Weird Al NEVER made a song about Barney on fire.
Avril Lavigne's Complicated
its a parody of "Ridin" by Chamillionaire
"I Want it That Way" by the Backstreet Boys
Its just the music of rage against the machine in general that hes making fun of.
"Piano Man" from Billy Joel.
He made a parody of "Bad" by Michael Jackson.
It's not making fun of a particular song. It's more just in the style of the 50's "Doo-wop", Elvis type sounds.
Black Gold Soul Asylum
Weird Al never does a parody of any song unless the musician who wrote that song gave him permission. So he was clearly not punished at all for that parody.
It's an original, not a parody. However, originals are often in a song style of another group. This one is like Guns 'N' Roses