Black Sabbath have received a lifetime achievement prize at the Ivor Novello songwriting awards.
Guitarist Tony Iommi picked up the trophy, confirming the heavy metal band would embark on their "final tour" next year.
Ed Sheeran was named songwriter of the year, while Boy George picked up an outstanding contribution award.
Clean Bandit beat Sam Smith and George Ezra to win the prize for most performed song for Rather Be.
The band thanked their piano and saxophone teachers, while co-writer Jimmy Napes - who also wrote Sam Smith's Stay With Me - dedicated the prize to his wife Matilda, "who the lyrics of the song were inspired by".
Rather Be also won best contemporary song, while the best album prize went to Bombay Bicycle Club's So Long, See You Tomorrow.
Irish singer-songwriter Hozier won 'best song musically and lyrically' for Take Me to Church.
"This time last year I was completely unknown and this music was written alone in my attic," he said.
"I'm so encouraged. This is a huge deal for me."
Annie Lennox was awarded the fellowship of the British Society of Songwriters, Composers and Authors (Basca) - the society's highest honour.
The singer, who started out in The Tourists and Eurythmics before going solo, was honoured both for her music and for her activism and philanthropy.
Admitting her to the Academy, Sir Elton John highlighted her campaigning for "women, human rights and, above all, the fight against HIV."
Dressed in a fluorescent orange suit, Lennox said: "I don't know what I would have done if I hadn't become a singer-songwriter because creating music was all I ever wanted to do.
"I'm incredibly privileged to become the first woman fellow of Basca," she added. "With this, the glass ceiling is broken."
Brian May presented Black Sabbath with their career award, to which drummer Bill Ward commented: "It's been a good 40 years. At least, I think it has."
Iommi earlier told the BBC that the band would hit the road one last time in 2016, following his being diagnosed with cancer.
"We've tried to cut down because of my treatments," he said. "We can't just keep going round like we used to."
Kylie Minogue presented Boy George with his outstanding contribution prize, telling him: "I am just one of the many, many millions of people you inspired."
In his speech, the former Culture Club singer recalled his schooldays when "all I did was look out the window and draw pictures of David Bowie."
Describing himself as "a melody writer who doesn't play any instruments," he said: "It's amazing I managed to have this 30-year plus career doing what I love. What a life."
Accepting his songwriting prize from Sir Elton John, Sheeran said: "This is the one award that really counts because it comes from people you respect.
"No offence to all the other ones, obviously."
Welsh band Manic Street Preachers were given the inspiration award, marking almost 25 years of agitprop rock anthems.
Guitarist Nicky Wire thanked the band's original lyricist Richey Edwards, who went missing in 1995, "for his beautiful and brilliant mind".
Songwriting had got the band through "a lot of tough times", he went on.
Wire's long list of thank yous also included Karl Marx, Philip Larkin, Allen Ginsberg and Abba.
Midge Ure and Bob Geldof received a special prize in recognition of Band Aid's 30th anniversary.
Ure urged the songwriters in the room to come up with a new charity song, "because I'm sick to death of hearing the old one."
"The song was always a device, because it's not a great song," added Geldof, who compared Ure's synthesizer riff to the Z-Cars theme.
Albert Hammond, writer of such hits as The Hollies' The Air That I Breathe, Whitney Houston's One Moment in Time and Starship's Nothing's Gonna Stop Us Now, won the award for outstanding song collection.
After watching a compilation of his biggest songs, he received a standing ovation at London's Grosvenor House for telling the audience: "In the '60s, I was a waiter in this hotel."
The Ivor Novello awards are voted for by songwriters, with judges this year including Gary Barlow, Guy Chambers, Nik Kershaw, Shaznay Lewis and Kim Appleby of '80s pop group Mel & Kim.
Now in their 60th year, they have honoured the work of more than 750 songwriters and composers, including the Beatles, Kate Bush and Sir Elton John.
The winners and nominees were:
Best song musically and lyrically
- Take Me to Church - Hozier
- Above the Clouds of Pompeii - Bear's Den
- I Forget Where We Were - Ben Howard
Best contemporary song
- Rather Be - Clean Bandit, featuring Jess Glynne
- Every Other Freckle - alt-J
- Two Weeks - FKA Twigs
- So Long, See You Tomorrow - Bombay Bicycle Club
- Royal Blood - Royal Blood
- Present Tense - Wild Beasts
PRS for Music most performed work
- Rather Be - Clean Bandit, featuring Jess Glynne
- Stay With Me - Sam Smith
- Budapest - George Ezra
Best original film score
- '71 - David Holmes
- Mr Turner - Gary Yershon
- The Boxtrolls - Dario Marianelli
Best television soundtrack
- The Honourable Woman - Natalie Holt and Martin Phipps
- The Mill (Series 2) - Samuel Sim
- The Suspicions of Mr Whicher: Beyond the Pale - Edmund Butt
Lifetime Achievement: Black Sabbath
Outstanding Song Collection: Albert Hammond
PRS for Music Outstanding Contribution to British Music: Boy George
PRS for Music Special International Award: Paul Williams
Songwriter of the Year: Ed Sheeran
The Ivors Classical Music Award: Judith Weir
The Ivors Inspiration Award: Manic Street Preachers
The Ivors Special Anniversary Award: Midge Ure and Bob Geldof, Band Aid
BASCA Fellowship: Annie Lennox