Complex sentence: While in 1979, Mano was shooting for a Telugu film for which the veteran M. S. Viswanathan was the music composer, it so happened that the original singer S. P. Balasubramanyam who was supposed to sing a song could not show up to the recording studio.
Split into simpler sentences: While in 1979, Mano was shooting for a Telugu film for which the veteran M. S. Viswanathan was the music composer. It so happened that the original singer S. P. Balasubramanyam who was supposed to sing a song could not show up to the recording studio.