The emergence of the digital sampler made sampling far more practical. Each note-message received by the sampler accesses a particular sample. The Akai S900 (1986) was the first truly affordable digital sampler. Tangerine Dream tracks have appeared on a number of sampler albums. Slayer released a promotional 3-track album called "Diabolus in Musica Tour Sampler". The song also features a synthesised shakuhachi flute generated with an E-mu Emulator II sampler. The first low-cost MIDI sampler was the Ensoniq Mirage, introduced in 1984. The third appeared on a promotional CD called "The Alternative Radio Sampler". Around this time he bought a sampler and keyboards to experiment with. This filter is called a Large Volume Water Sampler (LVWS). More recently, Roland introduced the "Groove Sampler" concept. In 1969, the English engineer Peter Zinovieff developed the first digital sampler, the EMS Musys. Note that dither can only increase the resolution of a sampler. Then one inserts an anti-aliasing filter ahead of the sampler. The IDS prefix stands for Island Disco Sampler.