"They're not all complicated," Ian Anderson says with a laugh. "Some of it, I have to say, is pretty easy."
It's a surprising revelation. Since the late 60s Anderson has led the prog rock behemoths Jethro Tull.
As a musical genre prog is notorious for its complexity. It's full of shifting time signatures, exploratory sonic journeys and, lets face it, a high constitution for pomp. It also demands nothing less than technical musical virtuosity.
As a band Jethro Tull is most famous for blending their hard rocking riffs with arrangements cribbed from classical music, a pastoral sort of Englishness, flashy jazz flourishes, high (and low) concepts and topping it all off with the unlikely sound of Anderson's dazzling flute prowess.
"Well, it depends on the song," Anderson explains. "We have straight ahead rock songs and some simple acoustic fun things but some of the music is more disciplined and does require a lot of preparation."
"There are some that sound easy but aren't and there are some that are quite difficult that maybe people don't appreciate how difficult they are to play, technically."
Throughout the 70s the band delivered many albums that would go down as prog-rock classics; the sinister Aqualung, the epic tour de force of Thick as A Brick and the hard rocking Minstrel in the Gallery.
Musically, the band members were no slouches. But their songs retained an easy accessibility even if they were sweating to perform it. Despite the odd 22-minute song here and there, Jethro Tull generally managed to avoid the worst excesses of the style.
What was their secret?
"There were bands where everything they did seemed to be an incredibly complex, detailed and noodly adventure," said Anderson. "They didn't always have the ability to just settle into a groove and deal with simple melodies and simple structures. Jethro Tull was able to do that because they were songs that allowed for relatively simple expressions and simple accessible music. It wasn't all complicated.
"But if you were Emerson, Lake and Palmer it was all complicated. If you were Yes it seemed to be all very complicated, or Genesis or whatever. We did mix it up and did balance the complex stuff with really simple straight ahead tunes. It didn't all have to be hard work."
I'd once heard that he'd wrote some of the band's most hard hitting songs, such as the chugging stomp of Locomotive Breath or the perverse power riff of Aqualung on an acoustic guitar. It's hard to believe. Is that an urban myth or is it true?
"Absolutely, yeah," Anderson confirms. "Acoustic guitar has usually been my instrument of choice for writing music. Because sitting in a hotel room somewhere you can't plug in the electric guitar. If I'm writing music or working on arrangements I can do that and be whisper quiet and not upset the guests in the next room.
"I'm quite used to using my imagination when it comes to thinking up musical lines that will be delivered in a way very different from the way that I'm writing the song or arranging it. You have to use your imagination. Beethoven sat at a piano writing symphonies for 80-piece orchestras. Just a man at a piano with a piece of paper. He had to imagine."
Then, a thought occurs to him and with an exasperated laugh he adds the kicker.
"And he was deaf!"
* Tickets to next Sunday's Jethro Tull show at the Aotea Center are available now for just $99 (plus booking & service fees) on GrabOne.