So I had heard some 'No Age' stuff and while it was reasonably decent stuff I certainly wasn't blown away. Live they are a totally different proposition. Intensely loud (my ears buzzed for ages afterwards) the focus shifts completely from the vocals to an intense noise assault via guitars and drums. Cracking stuff.
Another example would be 'Pete and the Pirates'. A smashing wee pop record that is tight and catchy. However seeing them live... amateurish; they looked like a bunch of twee students and the audience looked as though it was comprised of their friends and family. Ruined the album for me a wee bit.