A B M Shahidul Islam, known as S.I. Tutul, is a Bangladeshi singer and musician who is the lead singer and lead guitarist of the Dhrubotara Band. SI Tutul born in Kushtia Khulna Bangladesh. He also works in the Bangladeshi film industry. He won Bangladesh National Film Awards for Best Music Director (Daruchini Dwip, 2007), Best Music Composer (Bapjaner Bioscope, 2015) and Best Male Playback Singer (Bhalobaslei Ghor Bandha Jay Na, 2010; Bapjaner Bioscope, 2015).

Musical career
Tutul was a founding member of the band LRB. In 2005, he founded a band called "Face to Face" which was later renamed to Dhrubotara in 2011.

Tutul is a well-paid playback singer in Bangladeshi film. His style is a blend of Indian classical, western, and operatic traditions. Largely self-taught, Tutul had a proficiency for music from a very young age and after completing BA (Hons) and master's degrees at Chittagong University, he decided to pursue music as his career. His basis in music is the classical piano but can also play many other instruments, including guitar keyboard. Tutul is also a sound engineer. Most of his songs are tuned and composed by himself.

Tutul is best known for redefining contemporary Bangladeshi music. He has been hailed by many people in Bangladesh as the Shurer Karigor (he who creates melodious tunes and music).

In 2006, Bangladesh won an international film award from the International Film Festival in Chennai for the film 'Nirontor. Tutul was the music director of the film, which was selected as a Bangladeshi submission for Academy Award in 2006.'

In 2005, the noted filmmaker Mustafa Sarwar Faruki offered Tutul a movie called Bachelor which was a success and brought him nationwide fame as a composer. The movie won a number of international awards, especially for the song ‘Keu Prem Kore’ (‘Everyone Loves’) which was a hit in Bangladesh and was tuned, composed and sung by S I Tutul.

Tutul was helped much by Bangladeshi writer Humayun Ahmed, who died in 2012. Tutul tuned, composed and sang the majority of Ahmed's songs and considers him a major inspiration. Singers like Samina Chowdhury and Asif Akbar won national awards for the song ‘Amar majhe nei ekhon ami' which was tuned and composed by Tutul.

Tutul has performed on many concert tours around the world. He was appointed special ambassador in Bangladesh for a number of organizations. He composed and sung more than 500 film and Drama playback songs. He composed and sang many jingles, background scores, and title songs.