Dutch string player Mike Fentross is well known for performances on the lute, theorbo, vihuela, and Baroque guitar. He is the director of his own ensemble, La Sfera Armoniosa, and is an educator in the Netherlands. Fentross was a student of Toyohiko Satoh at the Royal Conservatory in the Hague in the late 1980s. He went on for further studies with Nigel North and José Miguel Moreno. Fentross did an apprenticeship as a continuo player with the group Les Arts Florissants and other European Baroque groups of the 1990s. He won the Van Wassenaer Competition in Amsterdam in 1994, and by the late 1990s he had, in the words of the School for Early Music, "earned his spurs" as an early music specialist who appeared on albums with top artists both inside and beyond the world of early music. These included Yo-Yo Ma, violinist Lucy van Dael, and conductor Jaap van Zweden. Fentross formed his own ensemble, La Sfera Armoniosa ("The Harmonious Sphere"), in 1991; the group has remained active into the late 2010s. He has also conducted larger productions, including one of Monteverdi's Vespers of 1610 at the Festival for Ancient Music in Utrecht, and a rare production of the early opera Dafne by Marco da Gagliano. Since 1997 he has taught lute and continuo at his alma mater, the Royal Conservatory in the Hague. His recording career has continued vigorously, in the capacities of soloist, ensemble member, and conductor. Fentross accompanied the BRISK recorder quartet on the 1997 recording Music of the Spheres, featuring English Renaissance consort songs and instrumental music. He has led La Sfera Armoniosa on several recordings, including La Lucrezia, a collection of Handel's Italian cantatas featuring contralto Sonia Prina, and a pair of rarely performed operas by 17th century Italian composer Francesco Cavalli, La Rosinda and, in 2019 on the Challenge Classics label, L'Ipermestra.