Fungi, you should realise, are nature’s greatest improvisers. At least, that’s the idea that underlies some of an evocative batch of new compositions from saxophonist Alex Merritt.

Confirmation, if needed, that creative musicians can find inspiration anywhere (*), and the reflections on mycelia that popped up in Merritt’s introductions have definitely led him to some interestingly knotty writing. He and his cohorts in a new quartet – Elliot Galvin on keys, Will Harris on bass and Dave Smith on drums – took it as a springboard for some quietly intense improvising of their own at this consistently rewarding gig.

The venue helped. Bristol’s Fringe Bar in Clifton has a very small back room – the sort it makes no economic sense for anyone to play in but rewards musicians and listeners with a great sound. If you want to be within touching distance of jazz-in-the-making, it is always a good bet.

That is also an aid to concentration, and Merritt’s writing and playing both call for close attention. His pieces usually delve into a nicely-poised post-bop sound mix, featuring unexpected twists and a broad rhythmic freedom. It feels like developed music, that nevertheless leaves a lot of room for the players to explore further.

His newly assembled quartet, I think their name was announced on the night, handled all the new material with aplomb. Harris nailed some interestingly lop-sided bass lines. Galvin responded thoughtfully to the challenges of the writing. The always hyper-alert Dave Smith, on only his second appearance with the band, created a constant, roiling undercurrent that kept everything animated even in quieter moments.

All three also offer a probing accompaniment to Merritt’s own soloing. An early notion that Mark Turner would enjoy playing these tunes returned a few times as the leader developed his clear-toned, thoughtful statements. That’s probably a matter of shared influences – Konitz, Warne Marsh and Lennie Tristano in particular – than direct inspiration, but the comparison does the younger man no harm. Other Merritt enthusiasms also surfaced. A piece drawing on one of Messaien’s “modes of limited transposition” was a perhaps unexpected highlight, sounding unusual, atmospheric and involving all at once. Less surprisingly, a contrafact of So What – Compressions – saw the quartet revelling in the familiar harmony, with a rousing piano excursion and Smith once again providing the kind of lift that really helps a soloist get airborne.

Add several other pieces drawing on fungal worlds, and arresting treatments of a couple of well-chosen set-closers from other hands – Jimmy Heath’s Gingerbread Boy at half-time and Wayne Shorter’s Prince of Darkness at the end of the evening, and we had some of the best reasons to squeeze into the back room of a pub for a couple of hours, and an impressive introduction to a very accomplished new quartet.

(*) In this case, one might guess, from Merlin Sheldrake )

REMAINING TOUR DATES

6 Feb St Andrews Church, Hove

8 Feb Southampton Modern Jazz Club

19 Feb The Nutshell Winchester

23 Feb The Bull & Gate, Kentish Town, London

25 Feb The Flute & Tankard, Cardiff