I’ve long been a fan of Australian band The Church. Peter Koppes and Marty Willson-Piper are two of a handful of guitarists who made me want to pick up the instrument decades ago. Their beautiful, interweaving guitar lines served as both a source of inspiration and also frustration for me over the years.

Yeah, frustration. See, I’ve sat down many times to work out their songs, sometimes successfully and sometimes not. Ironically, the unsuccessful attempts are not the frustrating part. I’m used to not always being able to work out what’s going on, and very often shooting for something and missing still lands you somewhere interesting. No, the frustration comes when I’ve been successful. On more than one occasion when I have worked out a section of their interplay, I’m left scratching my head thinking “How the hell would anyone know that THAT would work?”

Note, I’m not saying it doesn’t work. It clearly does. But I want to understand the theory that lead them to try it. They’ve done it too many times over too many songs for it just to be a happy accident. Is it just that I need to go deeper in my theory knowledge to get it? Are they looking at this instrument from a different angle than me, seeing something I’m not? No doubt they are, but what IS that angle?

Anyway, I stumbled across this article today which gave me some more clues, as well as some little solace. It’s from a few years ago in Australian Guitar magazine, and they address this exact topic:

“Peter’s warming up by now. “It’s funny though: on ‘Tantalized’ [single from Heyday, 1986] we did it at the ARIA Hall of Fame with an orchestra and the conductor was astounded that I was playing an F major 7 chord while Marty was playing a G or a C or something,” he laughs. “He didn’t know which side to go with!”

“Somehow we’d managed to suspend these two different choices about what the middle is without actually having a middle,” Marty explains.”

Further on:

“I’ve been studying musical theory because I’ve had to teach it, and I’ve recognised that the only harmonic thing close to what we do is jazz,” Peter explains. “Hendrix was veering close to this jazz kind of thing when he was doing seven-flat-ten chords like in ‘Voodoo Child’ and things like that. And we use a lot of open strings in our chords. A basic chord has three notes but between the two guitars and the chords we’re playing, we have the full spectrum. In musical theory you can go all the odd numbers – 1, 3, 5, 7, 9, 11, 13 – and I think we’re actually doing that.”

Searching a bit further, I found this interview with Peter Koppes:

“Also, adding 5ths and getting that harmonic interplay that creates sounds that are not actually what you’re playing but they’re extra sounds. I created a technique putting these guitar parts together – it’s also a bit of a banjo technique – the pedaling the strings. That banjo technique of rolling arpeggios with this harmonic interference, if you like, of particular 5ths included in the sound. We find these days, where Marty would play in C, I would play an F, then he’ll be playing a G and I’ll be playing a C.”

and

“I’m writing a book on guitar scales at the moment based on modal use of the pentatonic minor scale shifting for a major – doing all of the filling of the notes to make it either a major mode or minor mode. I add the flat 4ths, which in a minor scale it’s a flat 4th, but in major form it’s the minor 3rd which is the two aspects of the blues – the minor 3rd over major.”

This has at least given me more leads on what parts of music theory to explore, but I suspect I may need to wait for his theory book to be released for more insight.