music diminished the keytar's popularity during the 1990s, continuing on until the late 2000s when a major revival was sparked by artists and groups such as The Black Eyed Peas, Flight of The Conchords, Motion City Soundtrack, No Doubt, and Steely Dan. Another instance is in early 2008 with Snoop Dogg's music video for his single "Sensual Seduction", in which he uses a keytar as a throwback to old school bands. Notable manufacturers of keytar models have included Moog, Roland, Yamaha, Korg and Casio. As of 2013, the Roland AX-Synth, the Roland Lucina, the Alesis Vortex and Rock Band 3 Wireless Pro Keyboard, are the mass-manufactured keytars on the market. Examples 1980s–1990s The Moog Liberation was released in 1980 by Moog Music, and was considered the first mass-produced strap synthesizer. It included two monophonic VCOs and a polyphonic section that could play organ sounds. The neck had spring-loaded wheels for filter cutoff, modulation, and volume as well as a ribbon-controlled pitch bend. The Liberation had a single VCF and two ADS envelope generators. The Roland SH-101 is a small, 32-key, monophonic analog synthesizer from the early 1980s. It has one oscillator with two waveforms, an 'octave-divided' sub-oscillator, and a low-pass filter/VCF capable of self oscillation. When a shoulder strap is connected to it, and the small handgrip with a pitch bend wheel and a pitch modulation trigger is used, the SH-101 becomes a keytar. The Yamaha SHS-10, released in 1987, has a small keyboard with 32 minikeys and a pitch-bend wheel, an internal Frequency modulation (usually referred to as FM) synthesizer offering 25 different voices with 6-note polyphony. Onboard voices include a range of keyboard instruments (pipe organ, piano, electric piano, etc.); strings (violin, guitar, double bass, etc.); and wind and brass (clarinet, flute, trumpet, etc.). A larger model, the Yamaha SHS-200, was released the following year, and came with 49 keys and dual stereo speakers. 2000s–present The Roland AX-7, which was manufactured from 2001 to 2007, contains many more advanced features than early keytars. It has 45 velocity sensitive keys (without aftertouch), and a 3-character LED display. Several features aimed towards stage performance are present, such as a pitch bend ribbon, touchpad-like expression bar, sustain switch, and volume control knob, all on the upper neck of the instrument. There is also a proprietary "D-Beam" interface, made up of infrared sensors that detect nearby motion. This interface can be used