A dub reggae flavour on Theon Cross Intra-I track 'Forward Progression II' filters through joyously the pulse lingering long behind the beat.

It is the best of the pre-release tracks so far and certainly a long way stylistically from Cross' Fyah but only a few years in terms of the hands on the clock and a few dozen calendar months after all.

It brings on a flashback to sitting mind blown in Gearbox's tiny mastering studio a few years ago in the Tileyard on a chair perpendicular to the Studer ''baking'' tape recorder and over the shoulder a glimpse of the vintage in-house lathe when label head honcho Darrel Sheinman ushered marlbank to the ''x''-marks-the-spot listening chair to crank up a Theon track flavoured deliciously by Artie Zaitz certainly burns in the memory.

It was a straighatead rumbler, quite conventional perhaps in terms of a retro groove. But it worked and remains my favourite Cross sound. Later in Sons of Kemet soaked in the Shabakian vision Cross himself has moved on in terms of his sound and his label for his own explorations.

Still work in progress compared with his earlier triumph. Think: In early-New Orleans music brass as bass did the business. Later when you listen to old ska, still significant as a blend to UK jazz through Jazz Jamaica, it's usually trombone leading the charge so with the reggae flavour on this track that turns on a torch pointing in that direction.

Before when he was an unknown Theon was ace channelling mardi gras Indians and Big Easy street sounds with Tom Challenger and Brassmask in that early jazz domain going back to 2013, check that highly collectable Babel label release, again for a huge contrast to this new track.

As for 'Forward Progression II' better than the sleeker lines of early album introductory track 'We Go Again' and far more than the poppier 'The Spiral' featuring Afronaut Zu & Ahnansé.

One thing beyond snap likes, raves, get downs, caveats, chin-stroking is for sure Theon is changing the way we think about tuba even beyond his tech tinkering (such as involving avatars in a VR immersive space among recent news stories) but which are also interesting. As jazz is fundamentally about the rhythm section this is significant compositionally and this track suggests tuning in again. ''You gotta change,'' Miles Davis knew and did. It's a period of transition. Stephen Graham

Intra-I is out on 29 October