Paul Simon was just a teenager when he released his first single.

And since he and school friend Art Garfunkel - under the name Tom & Jerry - put out Hey, Schoolgirl, he's covered more musical ground than most artists that have come and gone in the intervening 60 years.

His forthcoming album continues that onward progression, and carries his career, in which he's barely put a musical foot wrong, well into its seventh decade.

Stranger To Stranger is his 13th album, his first since 2011's So Beautiful Or So What, and sees the New Jersey-born singer-songwriter fuse traditional folk with electronic beats, African, Indian and South American rhythms, while toying with the concept of microtonality - the idea music isn't formed of the 12 notes we recognise in Western music, but 43 notes, separated by tiny steps.

It gives it a bit of an otherworldly feel, as if recorded between awake and asleep.

To promote it, he's conducting a relatively rare series of interviews, and on the day of this conversation, says he's been enjoying them.

"It's a funny kind of work, if you can call it work," says the 74-year-old. "And I do get to the point where I get very tired of talking about myself - but don't worry, I'm not going to talk about myself or this record now."

He looks up, deadpan, before cracking a warm smile. He is, thankfully, joking, the wry humour found in many of his lyrics seemingly not reserved solely for his songs.

What actually transpires is something equal to an audience with Paul Simon, as he talks, extremely eloquently and almost without hesitation or repetition, for the best part of an hour about the new album, his approach to songwriting and beyond.

Questions aren't required: he covers all bases, aside from his one-time musical partner Art Garfunkel, with whom he no longer talks. (There was a warning from his publicist not to bring the subject up, or ask about the chances of another Simon & Garfunkel reunion.)

Also off limits is the matter of Simon and his wife Edie Brickell's 2014 arrest for disorderly conduct, following a 'rare argument' which reportedly resulted in Simon shoving Brickell, and her 'slapping' him (charges were eventually dropped).

Simon does mention Brickell today though, the singer best-known for her 1988 hit What I Am, with New Bohemians. A conversation between the pair gave him the idea for Insomniac's Lullaby, and she is referenced elsewhere on Stranger To Stranger, not least with the song In The Garden Of Edie.

There's a five-year gap since his last album, a pattern for previous records too, which suggests Simon really took his time recording it. He says that's somewhat deceiving, as he toured So Beautiful Or So What for 18 months after its release, and finished Stranger To Stranger more than six months ago.

"It's not as long as people think, or how it may look. My cycle is usually about three years, but this was a little longer because it was more difficult than the last couple have been. Why is that? It just is, and I suspect it will be like that from now on, if there is a now on," he remarks.

He explains that his past work makes it difficult for him to write new songs. Essentially, when you've set the bar as high as, say, Bridge Over Troubled Water, it's difficult to write new material that lives up to it.

It's not exactly modest talk, but then if you'd written Bridge Over Troubled Water, you wouldn't be modest about your achievements either.

"And I've written a lot of songs," he continues. "I do something and I think, 'I already did that', and I don't want to repeat myself, or I start a rhythm and it sounds like Cecilia, or Graceland or whatever.

"Not that I am opposed to using elements from old records," he adds. "In fact, I am very much in favour of using elements from old records, as it's a nice way of keeping a continuity of sound going through your music, but other songs I've written provide obstacles."

He knows when it's time to make another record: when he starts feeling anxious or depressed, he says - rather than succumbing to the emotion, he recognises it as signals to get working. From there, it might take him another six months to form a strong idea, and only then does the record begin to take shape.

"My ideas fall into two categories; ballads, or a more rhythmic premise. Ballads will have lots of chords and interesting phrases. The purest example of my rhythmic songs are on Graceland," he says, referencing his landmark 1986 album which saw him team up with African musicians, including Ladysmith Black Mambazo.

"When I've finished an album, I feel completely done and I have no idea what to do next," adds Simon. "And that's good, you don't want to finish a record thinking about all the things you wished you'd done, you want to have an empty tank. If I felt like I had something else, I would've continued until I ran out.

"I start from zero, which feels like not starting at all, and I end when I can't do any more."

Among a wide range of musical instruments used on Stranger To Stranger, from synthesizers and cloud-chamber bowls, to little-known African woodwind instruments and Peruvian drums, sits the chromelodeon.

The instrument was invented by 20th century composer Harry Partch, who devised a system of 43 notes.

"Partch said 12 notes in an octave was arbitrary division, and there were really 43 notes. Which I guess is arbitrary too, in a way, but that's the way he saw it.

"In order to compose using those notes, he had to invent something to play them, so he made about 10 different instruments," Simon explains, adding that he's since bought his own chromelodeon to use again.

What's also striking about Stranger To Stranger is the sense of space. While there are scores of different instruments on there, it never sounds as if more than a few are playing at once. That's all part of the plan, says Simon, who likes to take things away from his songs until there's almost nothing left, to see how they stand up.

"I might have something that's hampering the enjoyability of a song, and in that case, take it out and see what you have left. If you don't need to write something, or it doesn't need to be there, take it out and leave it out."

He says the best example of that comes from Simon & Garfunkel classic The Boxer, with its 'lie-la-lie' refrain. Simon actually sang that as a placeholder and meant to write some lyrics in at a later date, but couldn't think of anything that better suited the song, so it stuck, eventually becoming the most-loved thing about the song.

"But I never knew how things were going to be perceived," he admits. "And I never knew what was going to be a hit.

"I didn't know Bridge Over Troubled Water was going to be a hit - I'm really proud of it, it's really good, but I thought it was too long, and just a piano and voice...

"Who would have thought Graceland would be a hit? I could see it as a hit, but I could see it as a flop, too. The main thing is whether I think it's interesting," Simon continues.

"I didn't think 50 Ways To Leave Your Lover was going to be a hit, just as I didn't know [1997 soundtrack to his disastrous musical] Songs From The Capeman was going to be a flop, but it was a huge flop.

"You don't go into these things thinking about what comes after."

:: Paul Simon releases his new album Stranger To Stranger on June 3. He begins a UK tour on November 3. For dates, visit www.paulsimon.com