Forty years ago we all thought that the leading composer around 1400 was Johannes Ciconia, with various people called Zacara hovering in the background. Then came the documentation that nearly all the Zacaras were one person, that Ciconia was 40 years younger than anyone had guessed and that the newly reunited Antonio Zacara da Teramo was not only the true pioneer, particularly in the manner and style of Gloria and Credo settings, but also the composer of far more known music than Ciconia. And over the years, as new fragments of trecento polyphony were discovered, it turned out that Zacara’s music was also far more widely distributed than Ciconia’s.

It has been a long and often frustrating journey, with two more songs credited to him only two years ago. But while there are now two recordings of Ciconia’s complete works, Zacara has benefited from only scattered representation so far (including three CDs devoted to his music). Among the reasons for this is the distressing fact that so much of Zacara’s music survives with voices missing. Even so, challenges are there to be overcome, and Michele Pasotti got the three most active Zacara scholars on board, with reconstructions of all the missing voices or sections. (I would give much for information about who did which reconstructions, not least because they all seem to me utterly convincing.)

Another of the problems is that many of his last works have texts that are seriously problematic: they are crazy even by the standards of the wildest trecento music, and they are almost impossible to construe logically. (The French translations here are credited to Loïc Windels and represent a bold attempt; the less successful English translations are not credited.)

But with those details in place, the members of La Fonte Musica really go at the music for all they have. They show a wide range of colours and approaches, with a particularly free and flexible tempo: I can’t get over their sense of ensemble, which opens up the music so marvellously. Prime here are the soprano voices of Francesca Cassinari and Alena Dantcheva, who cover the most intricate difficulties with effortless aplomb and needle-sharp precision. (Yes: women alongside men in all that church music, but they sing so marvellously that nobody is likely to complain; for that matter they also use four fiddles, hard to document in polyphony that early.) And the gorgeously free lute-playing of Michele Pasotti helps us to understand how the remaining musicians combine stunning accuracy with flexibility and resource.

The music is distributed among the four CDs in a beautifully logical manner; and the booklet material includes lucid introductions to the music by both Pasotti and the three musicologists involved. Plainly this is an absolute must for anybody at all interested in music of the years around 1400.