Watching Jack Black play a new character/alter ego, a polka band leader:
1) This is the uncomfortable intersection between shtick, performance and satire.
2) It's not a very good polka song, or even a good song.
3) John Candy and Eugene Levy as brothers Yosh and Stan Schmenge did a much better job of spoofing/honouring polka.
4) I have inconsistent feelings and opinions when it comes to artists evolving through musical genres. When Charlie Watts wants to branch out on his own and explore jazz and graduate from the dirty adolescent phase the Rollings Stones incarnated, as he careened through his fifties and sixties, as contrasted with Mick Jagger still having to prance and preen on stage as a grandfather, I applaud that. Same with Bob Mould or Paul Westerberg or Paul Weller, starting out as punk/garage band members and angry young men, then mellowing out and turning more introspective and melodic. Better that than be Iggy Pop, still with his shirt off and playing the cuckoo bird on stage in his fifties.
Some progressions seem more manufactured. When critically-revile Metal Queen Lee Aaron decides to ditch the shiny bikinis and suggestive swords and becomes a jazz chanteuse, and tells me on MuchMusic with a straight face that this has always been her first love, I feel patronized and used. You lied to me before or you're lying to me now, but most probably you were lying both times and you're never not lying.
5) When Jack Black spoofs/honours 70s classic metal in Tenacious D, I buy in, completely.
But with the polka thing, I couldn't even get through the whole video. It's like this was his fifth or sixth best or last idea, like Mike Myers' "Love Guru".