Enigma is an electronic musical project founded by Michael Cretu, David Fairstein and Frank Peterson in 1990. Cretu is both the composer and the producer; his wife Sandra often provides vocals on Enigma tracks. The pair have also worked together under the name Sandra. Jens Gad co-produced and played guitar on three of the Enigma albums. Six studio albums have been produced under the name of the project. Enigma was among the first recording group to use direct to HD recording studio and non-percussion musical instrument and vocal samples, such as the iconic Shakuhachi flute and Gregorian monk chants samples on their crossover hit album, MCMXC a.D., which became a start of new music genre - "Enigmatic Music".