Joe Penhall was seen as one of ‘in-yer-face’ theatre’s leading lights in the 1990s, writing a few early classics (‘Love And Understanding’, ‘The Bullet’, ‘Some Voices’) but pretty quickly outgrowing that tag to produce major works (‘Blue/Orange’, ‘Landscape With Weapon’) that grappled with big issues to superb effect.

More recently he co-penned The Kinks musical ‘Sunny Afternoon’ and also has a Netflix TV show, ‘Mindhunter’, but his new play ‘Mood Music’ takes us back into the murky world of the pop industry.

It concerns two troubled protagonists: Bernard, a louche, self-centred, middle-aged producer/songwriter/multi-instrumentalist; and Cat, a talented, young, female singer/songwriter.

They are thrown together when he chooses her to co-write and sing a song on his album, but now a lawsuit is in the offing over publishing credit and also her claim of sexual harrassment/kidnapping. Who has the power? Who will prevail?

It’s an all-too-relevant tale given the Dr Luke/Kesha lawsuit and #MeToo movement. Penhall expertly digs into detail on the finer points of music copyright law, showing portions of Bernard and Cat’s fraught songwriting sessions. And there are some great laughs at Bernard’s expense.

But in order to crowbar in a lot of exposition and character motivation, Penhall also comes up with the device of structuring the play around the two main characters’ conversations with their lawyers and shrinks, with multiple flashbacks/flashforwards. This can be confusing, not to mention sometimes dramatically inert. The second act is much the same as the first. The impression is that it might all be going on in one of the main characters’ heads.

But Ben Chaplin gives a crackerjack performance as Bernard in a role that seems written for him. Basically, anyone who’s ever had more than the most rudimentary dealings with the pop business will have met someone like Bernard. He’s a close relation to Damon Albarn, Keith Richards and Mark Ronson.

There is also a genuinely dramatic moment when we finally see Bernard’s true colours, reminiscent of a similar note in David Mamet’s ‘Oleanna’, clearly a big influence on this play.

There are other problems with ‘Mood Music’: Cat, though certainly savvy beyond her years, looks about 18 rather than someone who’s been around the pop block a few times.

Also the music Bernard and Cat come up with – somewhere between Dido and Donovan – sounds unlike anything that’s been in the charts over the last 20 years. And the idea that Bernard would have Sonny Rollins on speed dial is peculiar.

And what about the ending? I won’t give too much away but will just say that most of the cast morph into a string quartet. Maybe it’s something to do with the sanctity of single-author works of art. Or maybe it’s as simple as: don’t you dare mess with the pop business…

(‘Mood Music’ has just finished a successful run at the Old Vic but will probably be back soon.)