Mr. Stephen. C Koshy had his formal music education on the American Organ and Piano with his father Oommen. C. Koshy,(affectionately known as Jacobs Baby) who himself was a renowned Composer/ Organist/Pianist in Kerala. He was a member of the Christ Church (CSI) Choir, Mavelikara under Mr Joseph Ittyerah (Acha Sir) and later on became the Organist.

He shot to prominence in 1973 when he won the 1st prize in the Organ recital in the Choir Festival at CSI Cathedral, Kottayam, Kerala. Later on, he won the 1st prize in the Instrumental Music category in 1974 State Youth Festival at Trivandrum.

Relocating to Hyderabad in 1977, he served as the Organist & Conductor /Director of Music at St. Georges Church, Abids, Hyderabad, from 1985 to 2000, He won accolades from the music lovers of Hyderabad for his repertoire on the Pipe Organ during this period. The performance of the" Mass in C " by Mozart on his death bicentenary celebrations in 1992 is being remembered by one and all.

He is the Founder Conductor of the Hyderabad Choral Society where he had conducted many concerts incorporating Secular/Jazz and Classical Choral works.

He is presently the Organist & Conductor of the Immanuel CSI Malayalam Church, Hyderabad where he has been a member since the year 1977.

He has also composed many English & Malayalam Choral works which are being sung by Church Choirs the world over. It may be remembered that the Singapore Malayalam Ecumenical Church Choir had sung his “Boat Song” for the Yearly Thanksgiving Service on August 14th, 2015 (on the eve of Independence Day) before the august presence of the President and the Council of Ministers of Singapore.
After retiring from Central Government Service, he continues his passion of teaching Western Classical Music [Piano, Guitar, Theory of Music, Singing (both Choral & Solo)] to his students at the Allegro Studio of Western Classical Music. His main passion has always been Church music. His students have become concert pianists and teachers of Piano & Western Classical Music in different cities of India and abroad.
He is the first composer from India who has his works published in the Musicalion website and he has been declared as the 'Composer of the day' by Musicalion in September 2023.