Some Elvis Costello fans regard his work now as the natural progression of one of the most talented songwriters of his generation, spurred on by the inspiration he gets from his new wife, Canadian jazz singer Diana Krall.
Others simply pine for the high-octane drive of his earlier work. They miss songs like "Watching The Detectives," "Pump It Up," "(I Don't Want To Go To) Chelsea" and "I Can't Stand Up For Falling Down."
Well, Costello is coming to Australia to let his fans know this: he can still rock 'n' roll with the best of them.
When Costello collaborated with Burt Bacharach in 1998, many long-time Costello fans were appalled their musical hero would commit such alleged musical heresy.
And after then writing all the music for a classical ballet adaptation of Shakespeare's A Midsummer Night's Dream, they went into near cardiac arrest.
The album, Il Sogno, was recorded with the London Symphony Orchestra and released on the same day as The Delivery Man. But fans wondered what their idol was thinking.
"When a group of really passionate Italian classical musicians come to you and ask you to write such a piece, it's an incredible compliment," Costello says. "Particularly when you have no track record as a classical composer. It's such a crazy notion; you realise these opportunities don't come along very often."
Not only did Costello face opposition from his regular fans, there was much disquiet among the classical music set.
People are very orthodox in their tastes and views and both sides had me pigeon-holed," Costello recalls. "And I don't like being pigeon-holed. In fact, I loathe it."
Besides, he says, he does not regard Il Sogno as a classical work and he has a very wry explanation as to why.
"I prefer to describe it as an orchestral work. It's my dance record and I regard it as my contribution to disco," he laughs.
As for the reactions of his fans, Costello says that they can take it or leave it.
"The reason the albums were released at the same time was to say that I value them equally. The classical fans and the rock fans could then work out for themselves whether they bought either album or neither."
Costello had already dabbled in classical music during the early 1990s. "I always liked classical and I did write quite a bit of stuff but I never really considered it good enough to release," he says.
"So it puzzles me why these lovely Italians came to me with such a crazy offer. Perhaps they thought they were playing some sort of joke and my initial response was to say no but they were just so passionate about having me I couldn't say no."
Costello's rock album with his band, Elvis Costello And The Imposters, allays fears he has given up on rock 'n' roll. It features driving rock and his trademark ballads, strongly reminiscent of the style of music that won so much acclaim in the late '70s and early '80s.
Costello's personal life, particularly his marriage to Krall (with whom he collaborates) has been a major settling influence.
"I have peace in my life," he says. "I'm working from a position of strength but that doesn't make me care less or be self-satisfied.
"It has given me power to look outside myself rather than contemplate my own misery."
The relationship with Krall surprised both of them. Krall had been through a particularly difficult period with the loss of her mother and both felt her music did not reflect the recent experiences of her life.
"I became really a sympathetic lyrical editor at first and then, bam, we got married."