Rapper-turned-singer Plan B has won three prizes at the Ivor Novellos, including best songwriter - presented by Sir Elton John - and best album.
The singer, real name Ben Drew, also won most performed song for She Said, telling the audience the more popular it became "the more I hated it".
Other winners included Tinie Tempah and Mercury-nominated Irish band Villagers.
Special awards went to Muse, Steve Winwood, Free founder Paul Rodgers and musicals legend Stephen Sondheim.
Presenting the songwriter of the year award at the event on Thursday, Sir Elton said Drew's The Defamation of Strickland Banks was the best album of recent years "by a million miles".
"I've played it so many times, I've bought countless copies, I've given it to friends, I've worn it out," he said.
Accepting the award, Drew said he had written the record "to get through to the underclass that society doesn't want to talk about".
"One day I got a letter from a kid who told me my record helped him get through his time in prison and he wanted to be a better person," he said.
"It was at that moment that I realised what I set out to achieve," said Drew.
Rapper Tinie Tempah's number one single Pass Out, co-written with singer and producer Labrinth, was named best contemporary song.
Tempah left the victory speech to his co-writer, telling the audience: "Seeing as at the last awards we went to, Labrinth went to the toilet when we won, he can do this."
Tempah later presented Dizzee Rascal with the Ivors inspiration award, saying he was "the reason I'm making music".
Former Mercury-prize winner Dizzee Rascal told reporters he had consciously gone from being an underground artist in his earlier career to "writing anthems".
"I've been exposed to a lot of events where I have 30,000 or 40,000 people in front of me.
"I wanted to have sing-alongs so I started writing tracks like Bonkers."
The most succinct speech of the afternoon came from Conor O'Brien, of Villagers, who won best song musically and lyrically for the Simon and Garfunkel-esque Becoming a Jackal.
"I think songwriting is self-rewarding so I accept this as something of a bonus on top of the incredible year we've had," he said.
Matt Bellamy, the singer with international achievement winners Muse, said he was "embarrassed" by prize presenter Jo Whiley's description of his band as "conquerors of the world".
Former Free and Bad Company singer Paul Rodgers, who in recent years has performed as Queen's lead singer, won the outstanding contribution to British music award.
Presenting the award, Island Records founder Chris Blackwell said when he had first seen Rodgers perform with Free in 1968, he had been "blown away" by "the voice" - later to became Rodgers' nickname.
Birmingham-born vocalist and guitarist Steve Winwood, who had his first UK number one - Keep On Running - with the Spencer Davis Group in 1966, won the outstanding song collection prize.
He said he had first played the music of composer Ivor Novello in the early 50s but "wasn't too taken with it at the time".
"But I've come to realise music is something that unites people through the years and I'm fortunate to be part of it," he added.
And composer Michael Nyman, winner of the classical music prize, said he was proud of his contemporary collaborations, describing himself as "the only opera composer who has worked with Brian Eno but not ENO - the English National Opera".
Stephen Sondheim, whose scores include Sweeney Todd and A Little Night Music and who wrote lyrics to Leonard Bernstein's music in West Side Story, was unable to pick up his special international award.
His friend, British actress Julia McKenzie picked up the award on his behalf explaining he could not fly over from the US because he had bronchitis.
Napoleon: Total War won best original video game score, composer Dan Jones won best soundtrack for Channel 4's Any Human Heart and John Powell won the best original film score for How To Train Your Dragon.