“After one of the early recording sessions, one of the RSNO violinists – I won’t say who so as not to embarrass her – pulled me aside and said: ‘You know, I can’t believe I’ve gone my whole life and never heard this music before.’”

The music that the mysterious violinist was talking about is a trio of works by three of the most accomplished, most influential but also most shamefully disregarded figures in African-American music in the 20th century – William Dawson’s rousing Negro Folk Symphony, William Grant Still’s jazzy Symphony No. 1 (“Afro-American”), and George Walker’s achingly tender Lyric for strings – all captured on a new recording from Linn Records, released a couple of weeks back, and also being performed live later this month.

It’s the conductor of both the disc and the concert, Kellen Gray – who also happens to be the RSNO’s Assistant Conductor – who’s talking about the project. And he’s hardly surprised at the anonymous violinist’s reaction. “I think where we are is that we’re realising we’ve missed something along the way – something really important – and we’re trying to find the pieces.”

It’s a feeling that Gray himself had, earlier in his career, when performing music by another overlooked Black composer, R Nathaniel Dett. “I’d never heard of him before. But when I was a violinist in an orchestra of all Black musicians playing his work The Ordering of Moses, it’s like I somehow knew how it was supposed to go. It was one of the most organic music making processes I’ve ever experienced. And it’s been the same with William Dawson, the same with William Grant Still.”

That uncanny familiarity is something Gray puts down to his own upbringing in South Carolina. “My first musical experiences were in church in a very small, rural town called Catawba, where I basically learnt music by rote. It was all about absorbing the music as organically as possible, and then performing it with maximum expression – in that case with just your voice, your hands and your feet. By the time I played violin for the first time, which must have been in the seventh or eighth grade, I adhered pretty rigorously to the classical style, but part of me always wanted to experiment and find different ways of playing.”

Alongside his diverse activities as part of his RSNO role, Gray is also now Associate Conductor of the Charleston Symphony in his birth state. “In Charleston I have my own purview of concerts, and I do quite a lot of the programming as well as some of the conducting.”

But back to this idea of missing something – or, perhaps, like the anonymous RSNO violinist, of discovering something that we’re shocked we didn’t know about already.

First, there’s the simple joy and passion of discovering this hitherto overlooked music. “I feel like these are sounds that people haven’t heard before,” says Gray, “and in the way that they relate to jazz and popular music, I think they’re actually ultra-relatable to today’s musical vernacular, particularly to young people.”

On a deeper historical level, however, it’s also a question of developing a broader awareness of music, of filling in gaps in our knowledge that we didn’t know we had, even (whisper it) challenging some of the received wisdom about what’s important and what’s not – attitudes that have been handed down unquestioned for decades.

“I hope that understanding what we’ve missed can show us how to value each other better,” says Gray. “What I really hope for in the musical world is that we can find a place where we appreciate a composer’s music based on what it is, rather than creating a value-based system based on the culture that the music comes from. I’m going to speak very honestly now: I think we’re at a place where we’re beginning to appreciate Black culture, and I hope that brings us to a place where we learn to appreciate Black people.”

Kellen Gray conducts the RSNO’s African American Voices concert at the Glasgow Royal Concert Hall on 23 November, www.rsno.org.uk The same music and performers are featured on the new African American Voices CD from Linn Records, www.linnrecords.com

Kellen Gray: 'We've missed something really important – and we’re trying to find the pieces'