GREATEST hits are not what they used to be. In the streaming era, why bother when people can make their own?

Almost 21 years after she first signed a record deal, Sophie Ellis-Bextor realised she needed to do something new. Speaking the morning after she opened her new Song Diaries tour at Cambridge's Corn Exchange, she says the traditional route no longer serves fans, nor artists.

“There had been talk of doing a greatest hits before,” she says. “But I've often thought: 'What would be the point of just putting all the songs in one place?' People don't really access music like that any more, and for me, it's just not very exciting. I thought it would be fun to do something really different.”

Released in March, The Song Diaries sees many of Ellis-Bextor's ice-cool dance hits reworked as orchestral numbers. Arranged by composer Amy Langley and produced, like Ellis Bextor's two recent studio albums Wanderlust and Familia, by Ed Harcourt, it works well, freeing the songs to explore a wider emotional range.

If noughties hits such as Take Me Home and Music Gets The Best Of Me seem a little flat today, The Song Diaries is like a 3D artwork, the songs opened out to reveal intricacies and new possibilities.

Murder On The Dancefloor – a number two smash in 2001 – is transformed into a percussion-driven epic which evokes images of Ellis-Bextor on horseback, galloping over rugged plains.

“I get horses in my head too when I sing that,” she laughs. “What you get in abundance with an orchestra, which you don't necessarily have in the originals, is romance, this tenderness. It was important to me that this revealed new aspects of the songs.”

She adds: “Some of them sound quite regal to me now, very British, like the soundtrack to some 1970s mystery. That's all part of the fun. I didn't want it to be po-faced and over-serious just because it was orchestral.”

Included is A Pessimist Is Never Disappointed, a track from her days as the teenage frontwoman of late 1990s indie band theaudience. A lot has changed since. Having married Richard Jones, the bassist from The Feeling, in 2005, she is now mother to five boys.

Jones will play in his wife's band on this tour, which will see them accompanied by newest arrival Mickey, born in January.

“It's fun to go back and sing a song you first sang 20 years ago and think: 'What is the thing I'm going to bring to this song now, and why?'” she says. “This is why it's called The Song Diaries, it's revisiting your younger self, looking at yourself then and now.

“It's also a different way to sing, more exposed. I didn't want to do Auto-Tune or double-tracking or have loads of backing vocals. I wanted it to sound as if I'd just walked into the room and started singing. It's very important to do things you haven't done before when you're getting a little too comfy.”

These concerts are split in two, with the 22-piece orchestra accompanying Ellis-Bextor for the first half of the night. Later, her band will join the throng for orchestral disco versions of the likes of Murder On The Dancefloor and Love Is You, the Carol Williams hit from 1977 sampled on Groovejet, her worldwide hit with Italian DJ Spiller in 2000.

“It's fantastic, an extraordinary thing for me to do these concerts,” she says. “It's quite a fun night out. Things start off really politely, with people wondering if they're allowed to cough and by the end they're dancing around in the aisles.”