There are many roles in the music business for those who don't play an instrument or have a note in their head. From the music hack and the promoter to the record-label dude and the roadie, there is something to suit all shapes and sizes. There is even, as Paul Simon put it so eloquently in Wristband, a need for bouncers to act like St Peter as they guard the dressing-room platters of bread, cheese and cold meats.

Perhaps the most pivotal offstage role is that of manager. As long as we have had fabled, famous and fabulous rock and pop stars strutting the stage, we’ve had someone watching their back.

Rock’n’roll lore has always had a lot of love and loathing for the manager. Such colourful characters as Colonel Tom Parker, Andrew Loog Oldham, Brian Epstein, Allen Klein, Peter Grant, Sharon Osbourne, Paul McGuinness, Louis Walsh, Troy Carter, Tina Davis, Scooter Braun and the rest of them have worked hard for their 20 per cent.

That’s how the managers have always rolled: they get a percentage of what their acts earn. They take a chance on the acts at an early stage. They invest in the act’s development. And they reap the rewards when the big time comes calling. A manger’s role is to look after the business side of the house, put a team together to work for the artist, and provide everyday counsel and advice when required.

Forensic audit

All managers will have probably kissed a few frogs before they found their lucrative princes or princesses, so no one really begrudges them their cash. Well, unless the act smells a rat, does a forensic audit and spots some creative accounting. Then, we’ll have a much different story.

However, hiring a manager and giving them 20 per cent of your income is not the only way to skin a cat. Billboard's recent report about the number of managers who are now on salaries rather than commissions illustrates that the picture is changing.

While none of the acts is paying peanuts for management services – Dan Rys’ piece spoke of salaries from $200,000-$500,000. But the kickback for artists such as Beyoncé, Taylor Swift, Bruno Mars and Ariana Grande is complete control. After all, if you are paying someone 20 per cent and not heeding their advice, why bother with the relationship?

Hard-nosed

It’s a sign of the times. In years gone by, when the bulk of an artist’s revenue came from music sales, it made sense to have a hard-nosed manager who knew where the bodies were buried in a label’s business affairs department. But at a time when artists are likely to earn money from dozens of different streams, they need to be working with people with a very different skill set.

That’s clear to see in the growth of large-scale management companies. By coming together, managers probably feel they can benefit from a collective expertise or knowledge bank. They may not have dealt with the ins and outs of a fashion-industry endorsement, for instance, but there may be someone in-house who has got that experience.

However, you can also see why acts may baulk at this. They are the ones who employ the manager, after all. They don’t want to be one of a hundred or more acts on a roster. They want a manager who has the answers when they have questions, and it makes sense for them to pay a salary or a fee for this rather than a percentage.

You have to wonder what Allen Klein, Peter Grant or Colonel Tom would make of this turn-up for the books.