Having a quiet night in over the weekend? We've got you covered with our top picks for Saturday and Sunday night's TV.

Saturday: Pitch Battle (BBC One, 7.30pm)

Reality formats based on hit films are nothing new, as The Real Exotic Marigold Hotel proved. But just because a TV series is inspired by blockbuster movies, that doesn't mean it can't become a powerhouse show in its own right.

After all, look what happened to Come Dancing when the word Strictly (from hit movie Strictly Ballroom) was added.

The latest small-screen show inspired by a big-screen smash (and its sequel) is Pitch Battle. It's a chance to fill the gap left by Britain's Got Talent a few weeks ago and steal back Saturday night viewers before The X Factor kicks off again in August.

Kelis, Gareth Malone, Seal and Joe Jonas are among those passing judgement, while Great British Bake Off veteran Mel Giedroyc returns to the prime time Saturday night slot after her stint on Let It Shine a few months ago.

The format is simple: each group displays their speciality with a 'showstopper' performance, before taking on their rivals in a themed 'riff-off'. The winning side will be decided by experts, including choirmaster Gareth, American singer/songwriter Kelis, and this week's guest judge, Bebe Rexha.

The show was inspired by Pitch Perfect, the Anna Kendrick comedy which was made for a mere $17million in 2012 and took the box office by storm. With tills ringing to the tune of $115million, there was no surprise when a sequel was rushed into production.

Producer and co-star Elizabeth Banks took over the director's chair, and though the budget was almost doubled, it proved even more successful a couple of years ago, with a $287million gross being music to its backers' ears.

A third film is released at Christmas, but it remains to be seen whether more a capella proves as compelling, or if fans will have tired by the format.

However, we can tell you that the stars of this strand can't wait to get started.

''I'm thrilled and excited to be part of this fantastic new show," enthuses Gareth Malone. "There's a wealth of singing talent in this country and I'm delighted to bring that to BBC One.

"To me this is about finding extraordinary groups who have the skill and personality to light up our screens.''

Kelis is also thrilled to be taking part: "It's kind of nice when things come full circle. I started singing in the choir as a child, so it's always been something special to me. Now here I am 20 years later as a judge on Pitch Battle."

As for the queen of cake-related quips, Mel can't wait to get a slice of tonsil-tickling action.

"I am so excited to be presenting this new show and PB will definitely be bringing some cracking music into people's living rooms every Saturday," she explains. "Not only are we going to be joined by some brilliant groups and megastar judges each week, but to top it all off my old mucker the original twisted choir starter Gareth Malone will be there too. What a combo."

Sunday: The Loch (ITV, 9pm)

Think of Loch Ness, and invariably, that elusive monster springs to mind.

Although reptilian beasties are not at the centre of this six-part drama, which began its run last week, there is a monster of a different kind on the loose.

A serial killer is targeting the locals, and it's up to local detective Annie Redford to stop the villain in his or her tracks before the body count spirals out of control. The problem is, she's inexperienced; this is Annie's first murder case and it will push her to her limits.

Playing her is Laura Fraser, an actress perhaps best known for her role as chemical company executive Lydia Rodarte-Quayle in Breaking Bad. Although her career in the US has been going well, she was pleased to be able to head back home for The Loch.

"I'd had four years of working away so the fact it was set and filmed in Scotland was a huge draw," she reveals. "Then when I read the scripts I was fascinated by all the animal symbolism. There's the Loch Ness monster, wolves, crows and the odd mutilated sheep, that I felt was quite unusual.

"I also liked the character of Annie, the village cop working on her first murder case. She is full to the brim of pent-up potential she has never got to use before. She's on the edge and could go either way. If this case hadn't come up that potential might have turned to bitterness, so although nobody wants to see a murder, for her as a police officer it enables her to focus her energies and start learning how to become a proper detective."

She adds: "It was also interesting the way she makes mistakes and is overwhelmed by it a little bit, not knowing what's the right way to go about things because she's never done it before, even though she's 40 years old."

Joining Fraser on screen is Siobhan Finneran as Annie's English boss, DCI Lauren Quigley. Thankfully, the two actress got on better in real life than their characters initially do.

"At first, Annie is desperate to impress Quigley," explains Fraser. "She admires and respects Quigley's work ethic and wants to prove herself to her and learn from her. But at the same time she is wrong-footed and compromised. Annie feels misunderstood and misrepresented. Then later on Quigley grows to like and respect Annie.

"Every scene I had with Siobhan, I couldn't stop laughing. She's just so hilarious, I couldn't keep it together!"

Despite being on fine form as a detective here, the Glasgow-born star admits she would probably make a terrible real-life crime-buster.

"I am absolutely hopeless and honestly can watch something for a second time and still know! I can re-watch something forgetting we had already seen it a year before, then get to the last part and still can't remember who did it."

With a bit of luck, the conclusion of The Loch will live longer in the memory than that!