Los Angeles, US: Bob Dylan is notoriously a man of few words when he's not singing, but he opened up at a gala tribute to him as he turned the tables on music critics.

The 73-year-old Dylan offered his own assessments of some fellow rock legends -- as well as undiplomatic write-offs of other musicians -- in an unexpected speech at a charity event ahead of the Grammy Awards.

Dylan was honored Friday night in Los Angeles by MusiCares, which raises money for musicians in need, with a star-studded concert and an introduction by former US president Jimmy Carter.

‘There is no doubt that his words on peace and human rights are much more incisive, much more powerful and much more permanent than those of any president of the United States,’ Carter said of the emblematic voice of the 1960s counterculture.

A who's who of music greats covered Dylan's work at the event including Beck, Tom Jones, Jack White and Crosby, Stills and Nash.

Bruce Springsteen joined Tom Morello for a harder-edged rendition of ‘Knockin' on Heaven's Door,’ while Neil Young closed with another Dylan classic, ‘Blowin' in the Wind.’

Dylan did not perform but instead gave a half-hour speech, staring down at a text on loose papers as if they were sheet music on a stand.

He ribbed music critics, saying that throughout his half-century career they have said of him: ‘I can't sing -- croak, sound like a frog.’

‘Why don't critics say that about Tom Waits?’ he said of the singer with the famously growling voice.

‘Critics say my voice is shot -- that I have no voice. Why don't they say those things about Leonard Cohen? Why do I get special treatment?’