Some musicians mellow with experience. Gruff Rhys, on the other hand, has always seemed like a laid-back guy - even after two decades in music, most famously fronting much-loved Welsh rockers the Super Furry Animals.

He's certainly at ease in solo mode: Candylion, Rhys's second solo album (released almost exactly one year after his acclaimed oneman debut, Yr Atal Genhedlaeth) is gently acoustic, resonantly tuneful and one of the first real delights of 2007.

'I had a lot of really mellow song ideas; I thought I'd get 'em out of the way so that we could make the next Super Furries album really loud and rockin',' explains Rhys in a sweetly sleepy burr.

'I love playing in the band but doing this record meant I could try incredibly indulgent things without pissing my friends off. I'd been listening to a lot of varied music - Turkish records, old library soundtracks, Daisy Age hip hop - things that could spell disaster for the purity of the Super Furries.'

There's a hint of irony in that last statement: SFA's work has essentially been multi-layered, including ambitious surround-sound DVDs (2001's Rings Around The World) besides instrumental and Welsh-language albums. Still, Candylion is Rhys's own distinctive recipe, steeped in nostalgia, from the sampled 1970s intro to the folky nursery rhyme of the title single.

Candylion is also depicted as a cute cardboard character - how was that crafted? 'Well, I had a general idea of Candylion's aura. I knew it wasn't a very slicklooking beast, so I asked designer Mark James to create something that looked a bit crap. It looks exactly as I envisaged.'

James also directed Candylion's lovely video, inspired by the old children's show Fingerbobs, and the album's vinyl version includes a flatpack kit to build your own Candylion.

Throughout, the album is downtempo but never dour. 'Yeah, it's like a slow, upbeat atmosphere.' That's particularly exceptional on the epic final track Skylon!, which makes a controversial subject (violent plane hijacking) sound strangely jolly - and which never drags, even at a lengthy 15 minutes.

'I didn't actually realise it was so long. I wrote the lyrics and it just dawned on me,' he chuckles. 'But it's such a fast-moving story. The central theme is that you've just gotta get on with whoever you sit next to. Once everyone deals with that, there's a happy ending. So the terrorism aspect is just a sub-plot.'

Elsewhere, the album is rich in dreamy, deep-toned romance (Lonesome Words), soothing psychedelia (Beacon In The Darkness) and rootsy funk (Gyrru Gyrru Gyrru). Rhys also ventures beyond English and Welsh on Con Carino, a surreal duet with Lisa Jen (guest vocalist throughout Candylion).

'I've written Con Carino in really terrible Spanish,' he says, sounding embarrassed and cheerful at the same time. 'I just relied on my Linguaphone knowledge; it's inspired by the Tannoy announcements on the Barcelona underground system, which uses this male/female double-act.

I imagined a duet in an engineering room. Actually, some of the lyrics are about football.'

Rhys likens this number to Europop songs whose vocalists clearly don't speak fluent English: 'At best, maybe it's a song that reaches the level of 2 Unlimited. I'll probably be the laughing stock of the Spanish-speaking world.'

But then, he has always been passionate about music with lyrics he doesn't understand. 'It's the emotion and voice that's important in a song, arguably. I think people are generally more open-minded nowadays. On my street in Cardiff, there must be about six languages spoken. Hopefully, there's now less need for me and the Super Furries to explain what it means to be Welsh. Geography is increasingly irrelevant in music. If you've got access to the Internet, you can be anywhere in the world.' Rhys himself magically occupies several places at once; besides his imminent Candylion tour (featuring support from Jen's band 9Bach), he's been preparing several projects with SFA, including a new DVD and instrumental recording, plus a full band album that he hopes will be released this year.

Which just leaves the new record he's working on with experimental hip hop producer Boom Bip: 'It's an album inspired by the life of car manufacturer John DeLorean - and his "gullwing" sports cars. It's got MCs on it and electronic pop; musically, it's all over the place.'

Surely all these visions make it tricky to focus? 'Well, it's like when you've started reading a book and then you get another one going at the same time. There are always gonna be too many enthusiasms to fit on the same record.' He laughs softly. Rhys never was a creature of convention - and he's all the more entertaining for that.

Candylion (Rough Trade) is out today. Gruff Rhys's British tour begins on February 26 in Newport (London's Queen Elizabeth Hall on March 2).