Sandhya started her musical training under the direction of Pandit Santosh Kumar Basu, Professor A Kannan and Professor Chinmay Lahiri. However, her guru was Ustad Bade Ghulam Ali Khan under whom she mastered Indian classical music.
Though classically trained, the bulk of her work consists of Bengali modern songs. She began her career in Mumbai singing Hindi songs, starting with a song in the film Anjan Garh at the age of 17. Following her marriage to the Bengali poet Shyamal Gupta she settled in her home city of Kolkata. Gupta went on to write the lyrics for many of her famous songs.
Her most famous collaboration is arguably with the Bengali singer Hemanta Mukherjee with whom she sang numerous duets, primarily as playback for Bengali films produced from Kolkata. Hemanta and Sandhya became known as the voices behind the pairings of the Bengali superstar Uttam Kumar and his numerous heroines. She also sang several of Salil Chowdhury’s hit Bengali songs, such as Ujjwal Ek Jhank Payra, regarded as a classic.
Some of her notable Hindi songs include Aa gup chup gup chup pyar karien with Hemant Kumar (Sazaa, 1951), Bol papihe bol re with Lata Mangeshkar (Tarana, 1951), Yeh baat koi samjhaye re (Sazaa, 1951) and Udaasiyoun mein nazar kho gayi (Fareb, 1953) – (Source – Wikipedia)