Mandolin and piano is as unlikely an instrumental pairing as you’ll find. Putting them together in a duo really shouldn’t work, but Chris Thile and Brad Mehldau clearly didn’t get the memo. This meeting of two masters of their respective realms is a spine-tingling triumph – a honky, gutsy, jaunty, darkly witty new musical alloy that is suitably strange yet strangely familiar.

Thile has spent the past 20 years rewriting the bluegrass rule book with his groups Nickel Creek and Punch Brothers, along the way acquiring an unprecedented virtuosity on his instrument and branching out into solo performances of Bach partitas and collaborations with everyone from YoYo Ma to Edgar Meyer.

Mehldau, too, aside from being the most copied jazz pianist of his generation, has shown an admirable tendency to mix outside his comfort zone, notably with producer Jon Brion on the rock-influenced Largo (2002) and with drummer Mark Guiliana on the superb Taming the Dragon (2014).

One can only hope, on the evidence of their first recording together, that there is more to Thile and Mehldau than just a fleeting collaboration. The 11 songs here dig down into the roots of American music, touching the common ancestry of jazz and country but coming up fresh and turned boldly to the post-genre future. Alongside some excellent originals are edgy readings of songs by Bob Dylan, Joni Mitchell and Fiona Apple. Scarlett Town, one of many highlights, is a dark murder ballad from Nashville duo David Rawlings and Gillian Welch, with Mehldau providing backing vocals to Thile's high tenor.

It takes more than virtuosity to make music send shivers down your spine. You need generosity and vision, impeccable taste and a willingness to take risks. Still, the fact that Thile and Mehldau are as fine a pair of instrumentalists as you’ll hear anywhere doesn’t hurt a bit.