When an instrument not usually associated with improvisation is introduced into jazz, it is usually regarded as something of a novelty, and not to be regarded with the same degree of gravitas that instruments more commonly used in jazz enjoy.

While there's no doubt that Daniel Herskedal is an instrumental virtuoso on tuba, and the bass trumpet as well, there is no denying these instruments can be something of an acquired taste. The question then becomes, is this a taste worth acquiring? Rummaging around the bass clef, however fluently, plus the occasional herculean foray into the treble clef, can be interesting for some, a chance to scroll through the social media feed for others.

Herskedal succeeds in live performance by winning his audience over by dint of his effervescent musical personality, but a recording robs us of this.

His music has to stand on its own. Here he creates a series of vignettes where tuba solos float on lush, deep multi-tracked chords produced by tuba and bass trumpet. It's a sound world that totters on the divide between of art and artifice.

East-West, a concert curated by Siggi Loch for his highly successful 2019 Jazz at the Berlin Philharmonic season, similarly brings a number of instruments not normally associated with jazz improvisation to the fore – geomungo, oud, guembri and cello amongst others. Here, the success of this album depends on how far you are prepared to go to accommodate sounds more normally associated with ‘World Music’ into the broad church of jazz.

Loch's ACT label has successfully set out its stall under the banner ‘music in the spirit of jazz’, and while some of the performances here stretch that precept, there is no doubt that in their own right they have an undeniable charm.

It means the beauty of the music of the South Korean quartet Black String; combined with the NES Trio based in Valencia and featuring Nesrine Belmokh, a French-Algerian singer/cellist, Majid Bekkas, an oud player from Morocco, and guitarist Nguyen Le from Vietnam. Music that reveals itself in the ear of the beholder.