Two Esbjorn Svensson Trio (EST) albums followed the Swedish pianist's tragic death in a scuba diving accident in June 2008.
Three months after his death at age 44, his record label, ACT, released Leucocyte, recorded in January 2007 in Sydney.
The next year, an anthology entitled Retrospective: The Very Best of EST summarised the previous decade of the band's career, but included no new material.
Both were critically well received. Leucocyte won Sweden's equivalent of the Grammy, and it was widely assumed that nothing further would be heard from one of the few jazz trios to have reached out beyond the jazz audience without compromising the music's integrity.
As it turns out, not so. More music was recorded during the Leucocyte sessions, and ACT released a second album, called 301. The album takes its name from the studio where the music was made.
Leucocyte was widely hailed as a creative peak for the trio, and as evidence that Svensson's career had been cut at the height of his powers.
The immediate fear this engendered was that any subsequent releases from those sessions were likely to be composed of barrel scrapings. It is a relief to find that this is not the case, and the prospect of more music by the trio being released is tantalising.
It would certainly have been possible to put out Leucocyte as a double CD, including the music presented here, but either the band or the record company may have felt that at a time when music can be downloaded for free, a double disc was too much for the market.
The retrospective also came out as a single CD, leaving the music on the group's first four albums unrepresented. A double CD may well have been what Svensson himself intended, though.
The sessions took place in the middle of an Australian tour, and apparently produced about nine hours of recorded music.
Only the surviving members of the trio know how much of that came up to their own standards, but we do know that they were taking a break from a series of concerts widely regarded as triumphs, including the performance released in 2007 as Live in Hamburg.
They were also becoming more involved in experimentation with the electronics with which their acoustic instruments were occasionally processed, and believed that they were making progress in a new musical direction.
Svensson had edited the recorded material down to around two albums worth of music at the time of his death, but the sorting process was not complete, and his surviving colleagues, drummer Magnus Ostrom and bassist Dan Berglund, apparently didn't feel up to finishing the task at the time.
Late last year they and engineer Ake Linton finally felt they were ready, and assembled a second album which can serve as a companion volume to Leucocyte while standing on its own merits.
Linton also engineered the sound for the trio's concerts, and had increasingly become responsible for making creative decisions live with regard to when sound processing and other effects should be deployed.
For the sessions that produced Leucocyte and now 301, he was engineering in the same way, adding distortion, feedback and other effects as the trio played - a bold approach given that if the acoustic instruments had been recorded 'dry', any processing decisions could have been reconsidered and altered. As it is, they are irreversible.
It is possible occasionally to wish this was not the case. The distortion of the piano, in particular, is sometimes jarring, but clearly it is intended to be.
Disregard the special effects, however, and you are left with what was undoubtedly one of the most intelligently empathetic piano trios in modern jazz, playing at the top of its form, so this is another album well worth having.
Given the extraordinary rapport they had developed over 15 years, it must have been hard for Berglund and Ostrom to pick up the pieces.
Berglund, always the most rock-oriented member of the group, later formed a 'prog rock' band called Tonbruket, who have recorded a couple of albums.
Last year Ostrom released a solo album, Thread of Life, featuring one tune, Ballad for E, recorded in New York with Berglund and guitarist Pat Metheny as a tribute to Svensson. A planned collaborative recording featuring Metheny with EST was one of a number of projects being lined up when the pianist died.
Let's hope there is more releasable material by this exceptional unit in the vaults - and not too much of it was first fed through special effects units.
Landmark EST albums.
Winter in Venice (Superstudio, 1997): with this album, the trio found authoritative form, and critics began comparing Svensson to Keith Jarrett.
From Gagarin's Point of View (ACT, 1999): here it becomes apparent that Svensson and his rhythm section could borrow from contemporary pop and rock intelligently, and without compromising their own jazz aesthetic.
Retrospective: The Very Best of EST (ACT, 2009): a good introduction to the band in the form of a 16-track sampler drawn from seven albums. Popular tunes from their concert repertoire included here are: Dodge the Dodo; Good Morning Susie Soho; Believe, Beleft, Below; Seven Days of Falling; and Viaticum.