PORRIDGE, BBC1, 9.30pm

THIS reboot of Porridge made me laugh, and it’s spectacularly rare for a prime-time BBC1 sitcom to get a giggle from me, but I can’t help wondering why they’ve made this show.

The original Porridge, with the great Ronnie Barker, obviously can’t be bettered, and the BBC surely know this, so why do a remake? There’s simply no point.

Kevin Bishop plays Fletch – or, rather, he plays Ronnie Barker playing Fletch. There are flashes of Barker in his quick, sarky manner and his constant gum-chewing.

In this remake, the modern Fletch is inside for cyber-crime, and he uses his wit and charm to compose letters for his cellmates to their disgruntled wives and useless lawyers. He writes passionately to an arsonist’s wife of the “smouldering embers of their love”.

Yeah it’s good, but it makes you want to watch old episodes of the original series on YouTube. So unless you’re a sitcom aficionado, why bother with the new one?

SING: ULTIMATE A CAPPELLA, SKY1, 9pm

THIS new seven-part series celebrates the skill of a cappella singing.

Hosted by Cat Deeley, it tries to do something a little different as I’m sure we’re all sick of TV singing contests.

Shows like The X Factor and The Voice celebrate singers who can belt out a tune and want to be Adele or Whitney. They all do the same numbers, in the same style, and the result is the same: a tearful winner who vanishes within days.

This series celebrates “a cappella” singing, which is singing without instrumental accompaniment. Therefore, the practitioners have to be good and strong, and able to do all the work without back-up.

In this contest, 30 groups take to the stage and are gradually voted out by judges – yes, it can’t help being a tiny bit X-Factorish, can it?