I thought that too.
I posted this link earlier.
These were the popular UK bands in the thirties and I mean popular.
It was what the public wanted and the band in the drama wouldn't have got a look in.
Jazz records by Afro/American bands were few and far between in the thirties especially in the UK and it's doubtful that the reporter would have had so many. They weren't something "you could nip into HMV's and buy." They'd have to brought over from someone from America.
That's not to say this couldn't be an enjoyable drama series for many, but it just doesn't "sound right." So I won't be watching any more of it.
I dont think it showed the band were popular, they would have been very much part of an underground scene.