Answer the question at the end by quoting:

A synthesizer (often abbreviated as synth, also spelled synthesiser) is an electronic musical instrument that generates electric signals that are converted to sound through instrument amplifiers and loudspeakers or headphones. Synthesizers may either imitate traditional musical instruments like piano, Hammond organ, flute, vocals; natural sounds like ocean waves, etc.; or generate novel electronic timbres. They are often played with a musical keyboard, but they can be controlled via a variety of other input devices, including music sequencers, instrument controllers, fingerboards, guitar synthesizers, wind controllers, and electronic drums. Synthesizers without built-in controllers are often called sound modules, and are controlled via USB, MIDI or CV/gate using a controller device, often a MIDI keyboard or other controller.
In the 1970s, electronic music composers such as Jean Michel Jarre, Vangelis and Isao Tomita, released successful synthesizer-led instrumental albums. Over time, this helped influence the emergence of synthpop, a subgenre of new wave, from the late 1970s to the early 1980s. The work of German krautrock bands such as Kraftwerk and Tangerine Dream, British acts such as John Foxx, Gary Numan and David Bowie, African-American acts such as George Clinton and Zapp, and Japanese electronic acts such as Yellow Magic Orchestra and Kitaro, were influential in the development of the genre. Gary Numan's 1979 hits "Are 'Friends' Electric?" and "Cars" made heavy use of synthesizers. OMD's "Enola Gay" (1980) used distinctive electronic percussion and a synthesized melody. Soft Cell used a synthesized melody on their 1981 hit "Tainted Love". Nick Rhodes, keyboardist of Duran Duran, used various synthesizers including the Roland Jupiter-4 and Jupiter-8.  Chart hits include Depeche Mode's "Just Can't Get Enough" (1981), The Human League's "Don't You Want Me" and Giorgio Moroder's Take My Breath Away (1986) for Berlin. Other notable synthpop groups included New Order, Visage, Japan, Men Without Hats, Ultravox, Spandau Ballet, Culture Club, Eurythmics, Yazoo, Thompson Twins, A Flock of Seagulls, Heaven 17, Erasure, Soft Cell, Pet Shop Boys, Bronski Beat, Kajagoogoo, ABC, Naked Eyes, Devo, and the early work of Tears for Fears and Talk Talk. Giorgio Moroder, Brian Eno, Phil Collins, Howard Jones, Stevie Wonder, Peter Gabriel, Thomas Dolby, Kate Bush, Enya, Mike Oldfield, Donal Lunny, Frank Zappa and Todd Rundgren all made use of synthesizers.  The synthesizer became one of the most important instruments in the music industry.

Did any other artists use it ?

The work of German krautrock bands such as Kraftwerk and Tangerine Dream, British acts such as John Foxx, Gary Numan and David Bowie,

IN: Namdev, also transliterated as Namdeo and Namadeva, (traditionally, c. 1270 - c. 1350) was a poet-saint from Maharashtra, India who is significant to the Varkari sect of Hinduism. He is also venerated in Sikhism, as well as Hindu warrior-ascetic traditions such as the Dadupanthis and the Niranjani Sampraday that emerged in north India during the Islamic rule. The details of Namdev's life are unclear. He is the subject of many miracle-filled hagiographies composed centuries after he died.

Namdev's padas are not mere poems, according to Callewaert and Lath. Like other Bhakti movement sants, Namdev composed bhajans, that is songs meant to be sung to music. A Bhajan literally means "a thing enjoyed or shared". Namdev's songs were composed to be melodious and carry a spiritual message. They built on one among the many ancient Indian traditions for making music and singing. Namdev's bhajans, note Callewaert and Lath, deployed particular species of Raag, used Bhanita (or Chhap, a stamp of the composer's name inside the poem, in his case Nama), applied a Tek (or dhruva, repeated refrain) and a meter than helps harmonise the wording with the musical instrument, all according to Sangita manuals refined from the 8th to 13th centuries.  The musical genre of Namdev's literary works was a form of Prabandha - itself a very large and rich genre that includes dhrupad, thumri, tappa, geet, bhajan and other species. In some species of Indian music, it is the music that dominates while words and their meaning are secondary. In contrast, in Namdev's bhajan the spiritual message in the words has a central role, and the structure resonates with the singing and music. The songs and music that went with Namdev's works, were usually transmitted verbally across generations, in a guru-sisya-parampara (teacher-student tradition), within singing gharanas (family-like musical units).  Callewaert and Lath state that, "each single song of Namdev is a musical and textual unit and this unit is the basis for textual considerations". The unit contained Antaras, which are the smallest independent unit within that can be shifted around, dropped or added, without affecting the harmony or meaning, when a bhajan is being sung with music. In Namdev's songs, the dominant pattern is Caturasra, or an avarta with the 4x4 square pattern of musical matras (beat).

About how many did he compose?

OUT:
Callewaert and Lath,