Jenni Heinrich and Anne Begg will take the stage tomorrow in Bendigo with the instruments for an evening of music.

The members of Bendigo group the Guitar Collaboration discovered the guitars were "sisters" by coincidence as they rehearsed in 2016, after placing the instruments end to end and noticing the wood-grains matched.

The master craftsman who made the guitars only made two a year at the time.

It is "almost unheard of" for two classical guitarists living in the same regional town to happen on sister instruments, but it is not the first "bizarre" coincidence in the pair's lives, Mrs Heinrich said.

Both fell in love with guitars at an early age, grew up with the same idols and travelled long distances to Melbourne for the same teachers, though they only met in 2014.

Mrs Heinrich said musicians developed strong bonds with their instruments.

"It's a very intimate thing. My guitar teacher from university approved the instrument before I bought it. I remember saying to him after I got it that I was utterly entranced. The novelty had not worn off and I could never wait to get back and play it again," she said.

"He said 'yeah, it's like a love affair'.

"Just recently I had to send it to an instrument maker for repair. While it was there I had my old student instrument and I said to Anne 'this is like playing on a wet face washer'.

"It doesn't sing, there's no depth or projection in it."

Having guitars with matching tones was vital, Mrs Heinrich said.

"A stringed-instrument can have a lot of different tone-qualities. Some are more closed and sound more 'medieval' whereas some are brighter and lighter," she said.

"These guitars are very special and blend beautifully. We are just very lucky to have them.

"And our backgrounds are very similar, our interpretations are very similar and we feel music in the same ways."

The Guitar Collaboration plays at the Capital's Bendigo Bank Theatre on Friday from 7.30pm.

They will be joined by friends, Jenny Gogolin (flute) and Pam Jackson (soprano).

The program will include guitar duets by Australian composers, a Spanish suite for guitar and flute and a collection of Spanish and British songs including Danny Boy and The Water is Wide.

For their finale, they will play an arrangement of the Scottish ballad, Sky Boat Song.

Tickets available at the door and online through the Capital's Gotix website.

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