Craig Gill, drummer of the Inspiral Carpets, has died at the age of 44.
A statement on the Manchester band's Facebook page said they were "absolutely devastated" by the loss of "our brother".
Gill was one of the founding members of the group, which he formed in Oldham in the 1980s alongside guitarist Graham Lambert.
The group's hits included Joe, This Is How It Feels, She Comes In The Fall, Dragging Me Down and Saturn 5.
Gill, who DJed at The Hacienda nightclub, was also a music historian and ran music-themed tours around Greater Manchester.
The band, which was pivotal in the so-called Madchester scene of the late 1980s and early 1990s, said it had been "honoured to work alongside him for the last 30 years".
In a statement, Gill's band mates said: "To say we'll miss him is an understatement.
"He was the beating heart of the Inspirals in more ways than one."
No details of his death have been released.
Former lead singer Tom Hingley wrote it was "terrible, sad news".
Who was Craig Gill?
Natalie-Eve Williams, Manchester Music presenter, BBC Radio Manchester
To everyone who knew him and the legions of Inspirals fans, he was just Gilly - passionate about Manchester, always asking about new bands and educating people about the city's rich musical heritage.
His hugely popular tours had visitors from far and wide and he had total joy on his face when proudly telling stories of Liam Gallagher's record-buying trips or Joy Division gathering on a bridge in the snow to create an iconic image - or indeed, tales of himself, as a young teenager in his beloved Inspiral Carpets.
He travelled the world with the band, notching up more than 10 top 40 singles and three top ten albums - winning an army of followers along the way.
A young lad from Chadderton who made an impression on people from all over the world, he will be sorely missed.
BBC News entertainment correspondent, Colin Paterson, said the news had come "absolutely out of the blue".
Fellow Mancunian musicians also tweeted their shock.
Former New Order bass player Peter Hook tweeted: "Craig Gill was 1 of happiest smiliest people I'd ever met in this business. Saw him not long ago his usual happy self, can't believe it. RIP".
The Madchester scene
- Madchester was born out of Manchester's clubs and venues - such as The Hacienda, The Boardwalk and The International - in the late 1980s
- It was a movement that mixed rock with dance music
- A number of the scene's bands achieved global success, including Happy Mondays, Stone Roses, Inspiral Carpets, James, The Charlatans and 808 State
- Releases were predominantly on independent labels such as Factory Records and Mute
- The scene was a heady mix of bright psychedelic colours, music and fashion, with people wearing flared jeans, tie-dyed T-shirts and beanie hats
- Madchester peaked between the summer of 1988 - known colloquially as the "Second Summer of Love" - and 1992
Who were the Inspiral Carpets?
Colin Paterson, BBC News entertainment correspondent
Inspiral Carpets were very much a part of the Madchester scene. Happy Mondays discovered them, early on they supported The Stone Roses and even helped the next wave of Manchester music by employing Noel Gallagher as their roadie.
Craig Gill joined them in 1986 at the age of 14 after meeting them in a car park when their drummer had not turned up for a gig. By 1989 they made up a tenth of John Peel's Festive Fifty - his annual list of favourite singles. The following year This Is How It Feels took them into the Top 20 and on to Top of The Pops.
Their debut album, Life, was only kept from the top of the albums charts by a Carpenters compilation. That August came what would be their peak - headlining The Reading Festival. In a memorable moment Craig Gill's drumming intro to She Comes In The Fall, was supplemented on stage by a full military marching band.
So big was Madchester at this time that they were even asked to provide the theme tune to the BBC Saturday morning kids TV show "The 8:15 From Manchester."
There would be two more Top 10 albums before they were dropped by their record company and split-up. Later there were reunions and the band continued to tour.