Bass-baritone Klaus Mertens is celebrated by critics as an “excellent master of his craft” for his “unique power of expression, his congenial timbre, his keen intuition for text, as well as his convincing manner of making music”. He has recorded more than 200 CDs, including the entire works of Johann Sebastian Bach and Dietrich Buxtehude. These testify eloquently to his art of singing, which spans a great arch from Monteverdi to his contemporaries. Characterized as “the most significant Telemann interpreter of our time”, Mertens received the Telemann prize of the city of Magdeburg in 2016. In 2019, he was honored with the renowned Bach medal of the city of Leipzig as the “ideal interpreter of Bach’s cantatas and passion texts”.

Tini Mathot was born in Amsterdam. She studied piano and harpsichord at the Amsterdam Sweelinck Conservatory.
She enjoys a close collaboration with her husband and former teacher Ton Koopman. Together they perform many popular and lesser known works, giving recitals and performing in chamber music projects in the major concert halls of Europe, the United States and Japan. Tini Mathot regularly appears as a soloist together with Ton Koopman in concertos for two (or more) harpsichords and orchestra. She has recorded double concertos of J.S. Bach, C.P.E. Bach, J.F. Reichardt and C. Schaffrath with the Amsterdam Baroque Orchestra.
Tini Mathot is a member of the Corelli Ensemble, whose members include Reine-Marie Verhagen. The ensemble was awarded the Diapason d’Or in France for its recording of Haydn trios (with Andrew Manze and Jaap ter Linden), issued by Erato. The CD recording of Schubert’s ‘Winterreise’, sung by the baritone Klaus Mertens with Tini Mathot playing an original Rosenberger fortepiano, was released in 2005, followed by a recording of J.S. Bach’s organ trio sonatas with Reine-Marie Verhagen (recorder) and Tini Mathot (organ and harpsichord) in 2008, both CDs issued by Challenge Classics.
In her capacity as producer for Ton Koopman’s Amsterdam Baroque Orchestra & Choir and also for other ensembles, Tini Mathot has produced numerous CDs for Erato, Teldec and Antoine Marchand/Challenge Classics, among other labels. She is the producer of the complete series of Bach cantatas by Ton Koopman and the ABO&C as well as the Opera Omnia of Dieterich Buxtehude, which Ton Koopman is currently working on. In addition to these activities Tini Mathot teaches harpsichord at the Royal Conservatory of The Hague.
 Tini Mathot plays on a fortepiano by Mathias Müller, Vienna c. 1810 (with a range of 6 octaves FF-f4, an Empire-style case with bronze fittings and Caryatid legs), from the collection of Edwin Beunk, Enschede (NL). The instrument is typical of the Viennese building style around 1810. Mathias Müller had a reputation as an innovator with regard to instruments and was ‘Kaiserlich-Königlich priviligiert’.