The Lord of the Rings star will be playing the Classic Grand on Saturday night with his band Beecake.
They're launching their second album, Blue Sky Paradise, a collection of catchy pop-rock tunes, and the title represents Billy's own way of looking at life.
"The idea is that looking out the window just now it's a gorgeous day and sometimes in modern society you're so tied up with stuff like mortgages that you actually miss what we're actually living in and how beautiful the world is," explains Billy.
"Just look at a David Attenborough show and you realise that. If you're worrying about getting a new car – who cares! As you get a bit older and mature a bit, you think about these things, and how life is much more about relationships, and enjoying this world that we all live in."
As a musician and an actor both on screen and the stage, it seems possible that Billy's own way of looking at the world was sometimes distracted by cramming so much in. But he was able to put his busy lifestyle to good use, writing several songs while on the road with the touring Sunshine On Leith musical.
"As it was a musical I had my guitar with me and was practising songs," says Billy.
"And I wrote a lot of this album while touring this show, so what was happening at that time, whether it was things happening personally to me or to my friends or just watching the news in a hotel room, it was all about that time in my life."
Billy's life has never been the same since he took the role of Pippin in the blockbuster Lord of the Rings trilogy. The series of smash hit films meant he was suddenly being recognised all over the world, and appearing at premieres before thousands of people.
Now the prequel, the Hobbit, has been released, and Billy has some advice for the likes of Martin Freeman, who stars in it.
"You can't explain what it's like touring the world with these films," he says.
"To go to Japan and have 100,000 people out in the street, it's a mad experience. So I'm looking forward to hearing what Ken Stott – who plays Balin the dwarf – and the others are making of it.
"I think I'll say that you need to take a step back from everything now and again. Just look at what it is as everything is so hectic – never let walking down the red carpet in front of all these people become a normal thing, as it's something very special."
However it's smaller stages that Billy now has his eye on. After his stint in Sunshine On Leith he's interested in securing more stage work, and looking out for any parts that might tempt him.
"I thought I'd been on stage a lot more in the past few years then I actually had, and during the tour I realised I hadn't been on stage with a play that was running for a while for years," he explains.
"Just getting up every morning and learning the routines with a cast that were all amazing and great singers was really exciting.
"I'd like to do more stage work in future. It's quite difficult as you have to book so far in advance and you can be doing other things too, so it has to be something you're really passionate about."
His music is the main aim at the end of 2012 though. This Saturday's launch gig may also come with a special Christmas surprise, as Billy gets into the spirit of the season.
"One of the boys said that we should bake mince pies for everyone, but I'm not sure we'll get that far, although you never know, " he laughs.
"I've never tried to cook them before! But I think we have to play a Christmas song, I think the crowd will be expecting that. We better get our heads down and learn one-"
n Beecake, Classic Grand, Saturday, £10, 6:30pm. Blue Sky Paradise is available to buy through www.beecake.com.