The music publishers who suggested Tim O'Brien and Darrell Scott get together with the possibility of creating a successful songwriting partnership achieved something infinitely more rewarding. Sure, the pair produced a hit, When There's No-One Around, for Garth Brooks, quite soon into their relationship, but it is their shared chemistry as live performers that carries the real value.
This was the case when they first appeared in Glasgow as a duo, in a gig at Sloans in Argyll Arcade back in the 1990s, and they sounded as if they had known each other for 20 years (it was closer to 20 weeks). It is more so now. There is something enriching, even nourishing, about the way these two renew the traditions of Appalachia, where the blues and church music co-mingle naturally, with the immediacy and intimacy of a back porch or coffee house session but with the quality of the concert hall.
Old songs are updated, such as Old Joe Clark's scintillating renovation in tribute to Earl Scruggs and Pete Seeger, with a ridiculously accomplished guitar break from Scott, and their own songs tap into the same root with perhaps more worldly and harmonic sophistication, but with a core of sung-from-the-heart honesty.
They will take verse about and trade instrumental choruses - Scott on guitar, O'Brien on mandolin, fiddle and banjo - as if sharing the same heartbeat, and when Boston-based singer Aoife O'Donovan slips into a jaw-droppingly good, backwoods choir reading of Hank Williams' Alone & Forsaken as a cameo, she is accommodated like a sister.
All that was missing was a sign outside saying: "Soul food now being served."