By Will Smale
Business reporter, BBC News, May-Fair concert
"These are people I've made multi-millionaires, these are my guys," says hedge fund founder Saleem Siddiqi enthusiastically.
Clutching a beer, an effervescent Mr Siddiqi is chatting before the start of a charity rock concert he has co-organised in central London.
Taking place at the plush Café de Paris nightclub off Leicester Square, it isn't an event you would have found in any listings guide.
Instead, this is an exclusive invitation-only concert for hedge fund managers by hedge fund managers, the go-getting but mysterious investment bankers who some say are taking over the world.
With six bands all comprising members of the hedge fund industry due to perform - some of whom have flown in especially from New York - it is the super-rich at play.
And as more than 500 of their industry colleagues throng the free bar before the first act goes on stage, the collective wealth below the chandeliers of the opulent ballroom is hard to fathom.
Not that a member of the public would be able to guess, however - if they had managed to get past the strict security on the door. To the untrained eye it looks like a typically boozy office party, or possibly a school reunion.
The wives, girlfriends and female workers may look decidedly glamorous in their posh frocks, but the men, who outnumber them by about three to one, look rather more down-to-earth.
Aged from early 30's and upwards, most of the men are dressed in a combination of a suit jacket and more casual trousers, unbuttoned shirts tucked in. You'd be hard pressed to guess that most of them could buy the building.
'Great bonding experience'
Even the band members are self-effacing - at least before they get up on stage and the showmanship gets the better of them.
All the performances were well polished
They may be high-powered, super-wealthy go-getters in their day job, but as musicians they have a teenage-like enthusiasm for "rocking out".
They also take their performances very seriously, with some expressing endearing worries about the other bands over-running their slots.
"Playing guitar is kinda like my midlife crisis," says Chris Heasman of Lazard Asset Management, who together with his fellow bandmates have flown over for the gig from New York.
"It is a lot more fun than the day job, and a great way to release stress," he adds before performing his band's first song while standing on one of the amplifier stacks.
"Playing in the band is a great bonding experience," adds singer and multi-instrumentalist Brad Cole of Chicago-based Cole Asset Management.
"I don't play golf, so it is a good way to get together with the guys."
As the free alcohol continues to flow generously and the first bands take to the stage, it is obvious that the hedge fund managers find time to practice their music.
WHAT IS A HEDGE FUND
High risk, high return investments
Controversial as lightly regulated
Aimed at wealthy investors
Some require minimum personal investments of more than £100m
With the amps turned up to 11 and the spotlights on the stage, it is undeniable that all the bands, some of which include female members, can play well.
As they all belt out covers ranging from The Beatles' Revolution to Thin Lizzy's The Boys Are Back In Town and Van Morrison's Brown Eyed Girl, their enthusiasm gets the audience dancing.
And soon, watching middle-aged men dance badly to middle-aged men playing elongated guitar solos turns out to be much more fun than anyone could have expected.
There is, however, a serious side to the event: raising money for charity A Leg To Stand On.
Organisers Mead Welles and Saleem Siddiqi
Founded by New York-based hedge fund boss Mead Welles, it raises funds to buy artificial limbs for disabled children in India and other developing countries.
To attend Thursday night's rock concert in London, which Mr Welles organised with London-based Mr Siddiqi, guests had to pay £125 a ticket, with hedge fund companies donating more through sponsorship or by taking a table.
This is the first concert the organisers' two firms - Octagon Asset Management and Tapestry Asset Management respectively - have organised in London. Previous gigs in New York have raised more than $250,000 (£127,000).
"It shows people that we have a heart and want to do a good thing," says Mr Mead.
"We are helping people who really need it."
Yet as everyone freely admits, the concert is also a great networking opportunity for the tight-knit hedge fund community.
Some of the hedge fund guys were younger than others
"Doing what we do, it is important to have these people as friends," says Mr Siddiqi.
Back on the stage, the lead singer of a band called The Subscribers is whipping the crowd up into a fury.
With impressive Mick Jagger mannerisms, he sticks his tongue out below his shades and asks the crowd: "To all my friends in London, is anybody loaded?!"