Session musician and orchestrator During the 1970s, Ilaiyaraaja played guitar in a band-for-hire, and worked as a
session guitarist, keyboardist, and organist for film music composers and directors such as
Salil Chowdhury from
West Bengal. Chowdhury once remarked that "[Ilaiyaraaja] is going to become the best composer in India". "Our main guitarist in Madras is the best composer in India", he said. After being hired as musical assistant to
Kannada film composer
G. K. Venkatesh, he worked on 200 film projects, mostly in Kannada cinema. As Venkatesh's assistant, Ilaiyaraaja would
orchestrate the melodic outlines developed by Venkatesh, and learn about composing under Venkatesh's guidance. During this period, Ilaiyaraaja also began to write his own scores. To listen to his compositions, he used to persuade Venkatesh's
session musicians to play excerpts from his scores during their leisure times.
Film score composer At the start of his career, the music sensibility of Ilaiyaraaja was very different to the film music composed in those days. Even though he spent a lot of his time learning, he "wasn't able to grasp how music was being made for films." However, in 1975 when film producer Panchu Arunachalam was impressed by a song Ilaiyaraaja casually sung, he commissioned him to compose the songs and film score for the Tamil film
Annakili (1976). For the soundtrack, Ilaiyaraaja applied techniques of modern popular film music orchestration to Tamil
folk poetry and
folk song melodies. This resulted in creation of a fusion of Western and Tamil idioms. Initially he was little apprehensive about how his work would be received, he thought musicians in the industry may write him off. However, when
Annakili released in 1976, the music became a huge hit. For his following 12 films, Ilaiyaraaja based his compositions on the contemporary film music. Later, when a new wave of films started to come, they opened the space for the kind of music he wanted to explore. Ilaiyaraaja's use of
Tamil folk music in his film scores injected new life in the Indian film score milieu. By the mid-1980s, he started gaining increasing stature as a composer and music director in the
South Indian film industries. He worked with Indian poets and lyricists such as
Kannadasan,
Vaali,
Vairamuthu,
O. N. V. Kurup,
Sreekumaran Thampi,
Veturi,
Acharya Aatreya,
Sirivennela Seetharama Sastry,
Chi. Udayashankar and
Gulzar. Most of his compositions were sung by
S. P. Balasubrahmanyam,
S. Janaki and
K. S. Chithra.
Non-cinematic output Ilaiyaraaja's first two non-film albums were explorations in the fusion of Indian and Western classical music. The first,
How to Name It? (1986), is dedicated to the Carnatic master
Tyāgarāja and to
J. S. Bach. It features a fusion of the Carnatic form and
ragas with Bach
partitas,
fugues and
Baroque musical textures. The second,
Nothing But Wind (1988), was performed by flautist
Hariprasad Chaurasia and a 50-piece orchestra and takes the conceptual approach suggested in the title—that music is a "natural phenomenon akin to various forms of air currents". He has composed a set of Carnatic
kritis which were recorded by electric mandolinist
U. Srinivas for the album ''Ilayaraaja's Classicals on the Mandolin
(1994). Ilaiyaraaja has also composed albums of religious/devotional songs. His Guru Ramana Geetam
(2004) is a cycle of prayer songs inspired by the Hindu mystic Ramana Maharshi, and his Thiruvasakam: A crossover
(2005) is an oratorio of ancient Tamil poems transcribed partially in English by American lyricist Stephen Schwartz and performed by the Budapest Symphony Orchestra. His most recent release is a world music-oriented album called The Music Messiah'' (2006). In 2025, he became the first asian to debut a western classical symphony in London. He composed his first English classical symphony “Valiant”, performed by
Royal Scottish National Orchestra. In May 2020, he composed a song titled
Bharath Bhoomi, as tribute to the people working amid
COVID-19 pandemic. The song was crooned by
S. P Balasubrahmanyam and the video of the song was unveiled by Ilaiyaraaja on his YouTube channel on 30 May 2020, in Tamil and Hindi. On his birthday in 2020, Ilaiyaraaja announced the upcoming launch of his 'Isai OTT'
app. He stated that the app would contain much more than just his songs, like behind-the-scenes trivia about how each song was conceived, produced, and delivered, as well as collaborations with other musicians. Ilaiyaraaja's song 'Naanthaan Ungappanda' from the 1981 film
Ram Lakshman was part of the playlist for the opening ceremony of the
2012 Summer Olympics. His compositions
Paayum Puli Title Music and
Ilamai Itho were part of the soundtrack of
Ashim Ahluwalia's 2012
Cannes Film Festival entry,
Miss Lovely.
The Lovebirds (2020) incorporated a section of Ilaiyaraaja's "Oru kili" soundtrack composed for the movie
Aanandha Kummi (1983) as background music in its official trailer.
The Black Eyed Peas sampled the Ilaiyaraaja's composition "Unakkum Ennakum" from
Sri Raghavendra (1985) for the song "The Elephunk Theme" in
Elephunk (2003). Ilaiyaraaja's song "Mella Mella Ennaithottu" from
Vaazhkai was sampled by Rabbit Mac in the song
Sempoi. Popular American rapper
Meek Mill sampled one of Ilaiyaraaja's hit songs for
Indian Bounce. The alternative artist
M.I.A. sampled "Kaatukuyilu" from the film
Thalapathi (1991) for her song "Bamboo Banga" on the album
Kala (2007). Alphant sampled Ilaiyaraaja's music for his song
An Indian Dream.
Gonjasufi sampled Ilaiyaraaja's "Yeh Hawa Yeh Fiza" from the movie
Sadma.
Live performances Ilaiyaraaja rarely performs his music live. His first major live performance since his debut was a four-hour concert held at the
Jawaharlal Nehru Indoor Stadium in Chennai, India, on 16 October 2005. He performed in 2004 in Italy at the Teatro Comunale di Modena, an event-concert presented for the 14th edition of Angelica, Festival Internazionale Di Musica, co-produced with the L'Altro Suono Festival. A television retrospective titled
Ithu Ilaiyaraja ("This is Ilaiyaraja") was produced, chronicling his career. He last performed live at the audio release function of the film
Dhoni and before that, he performed a programme that was conducted and telecasted by Jaya TV titled
Enrendrum Raja ("Everlasting Raja") on 28 December 2011 at Jahawarlal Nehru Indoor Stadium, Chennai. On 5 September 2012, Ilayaraja performed in a live concert in Chennai with the
Hungarian National Philharmonic orchestra; during this event the music launch of his films
Neethaane En Ponvasantham and
Yeto Vellipoyindhi Manasu took place. On 23 September 2012, he performed live in
Bangalore at National High School Grounds. On 16 February 2013, Ilayaraja made his first appearance in North America performing at the
Rogers Centre in Toronto, Canada. The Toronto concert was promoted by Trinity Events for Vijay TV in India and produced by Sandy Audio Visual SAV Productions with PA+. Following his show at Toronto, Ilaiyaraaja also performed at the
Prudential Center Newark, New Jersey, on 23 February 2013 and at the
HP Pavilion at San Jose on 1March 2013. After his North America tour, he made a live performance at
The O2 Arena in London on 24 August 2013, along with
Kamal Haasan and his sons
Yuvan Shankar Raja and
Karthik Raja. ==Musical style and sensibility==