Organist, harpsichordist, conductor, teacher, enjoyer of good food and wine, devoted fan of big-band jazz, lover of the English countryside John Toll helped form some of the outstanding ensembles in the early music renaissance of the last quarter-century. Through dozens of recordings and countless concerts he established a reputation as one of the best keyboard continuo players anywhere. The art of adding harmony to a bass line to enhance its essential role in the music of the 17th and 18th centuries has rarely been more comprehensively mastered, or better taught.

It was a job as the keyboard player to the Bournemouth Symphony Orchestra and Sinfonietta that he first encountered a really good harpsichord (by Michael Johnson -Toll immediately ordered one for himself) and here where we formed our first ensemble devoted to baroque chamber music. Of course, we still played on "modern" string instruments, which were all we had; it was Toll's intense curiosity about the newly developing world of "historically informed" performance that took us to a workshop taught by the Belgian baroque violin pioneer Sigiswald Kuijken, which in turn led to my own career on baroque violin.

Back in London, we formed L'Ecole d'Orphée in 1975, to play baroque chamber music on appropriate baroque instruments. Among the other founder members were Ingrid Seifert and Charles Medlam; in 1977 they founded the ensemble London Baroque, and Toll joined them in 1978. In the following 10 years they played an astonishing 528 concerts together, and made 18 recordings of music ranging from Marin Marais to Mozart, from sonatas to opera.

Astonishing in that, at the same time, he was establishing himself as the first-choice keyboard player for Andrew Parrott's Taverner Players and Roger Norrington's London Baroque/Classical Players. As the early music world developed in the 1980s and 1990s Toll became an ever more central figure.

In the 1990s he co-founded two new ensembles, Musica Secreta with singers, and Romanesca with the lutenist Nigel North and the violinist Andrew Manze, thus helping to launch the career of one of the more recent stars of the early music scene. John Holloway