Shashi Hegde (shashivh@yahoo.co.in)
When you sit and wonder what made S-J click with classes and masses alike, you come across some aspects which were responsible for it. Their versatility, thorough knowledge of all forms of music and instruments, ability to set their own rules which others would follow, ability to take out the best from the singer and singer selection for the song, precise knowledge of orchestration and you can name many more.But the one of the most important factors responsible for their emphatic success is their association with Shailendra and Hasrat Jaipuri. When a composer works with a core team for a period of 20 years, each member of the core team will know the pulse of the other. 
Shankar and Jaikishan exactly knew what they wanted from Shailendra - Hasrat and vice versa.S-J decline started only when this core team broke with the death of Shailendra.Look at the statistics I compiled with the best of my information based on the original sound tracks of s-j films. ( Eg: Mein gaoon tum so jao - though the lyrics are same for both happy and sad versions, it is counted as 2 songs. Similarly for other films.)These are some stats of the golden era of S-J films from 1949 to 1968, that is from Barsat to Brahmachari spanning 96 films(All S-J films up to 1968 except Duniya and Kanyadan):Total number of songs: 783Written by Shailendra: 395Written by Hasrat Jaipuri: 362Written by Shailendra + Hasrat : 1Written by others: 25 (Rajinder Krishen 8, S.H.Bihari 2, Jalal Malihabadi, Ramesh Shastri, Deepak, Mirza Ghalib, Sant Kabir, Faiz Ahmed Faiz, Kamalesh Verma, Prem Dhawan, An English song from Sangam - 1 each and 6 traditional songs)Make a simple calculation, 97 per cent of S-J songs spanning 20 years and 96 films had lyrics by Shailendra and Hasrat. Sant Kabir, Mirza Ghalib and traditional songs cannot be counted as lyricists who were engaged for the film. So, of 783 songs only 15 songs were written by persons 'outside' S-J core team. Compare this stats with the other composers in the same period:S.D.Burman used Sahir, Majrooh, Shailendra and HasratNaushad used Shakeel Badayuni, Majrooh and SahirRavi, Roshan, Madan Mohan, Salil Choudhary, C.Ramachandra worked on and off with Rajinder Krishan, Shakeel, Majrooh, Shailedra and others. So is the case with Hemant Kumar, O.P.Nayyar, Kalyanji-Anandji, Sardar Malik, Chitragupta, Vasant Desai and others. It is 2 quality composers working in tandem with 2 quality songsters continuously over 20 years made all the difference.I guess no composer-lyricist combo has broken this record of 97 percent. May be Laxmi-Pyare- Anand Bakshi are next in the list. But what counts is not the numbers alone but the quality too. When you consider this, L-P lag far far behind.Even when you take in to account all S-J songs recorded from 1949 to 1991:Out of 1301 songs(Includes Tamil and Telugu dubbed versions of a couple of R.K Films and a Gujarati film), Shailendra (402) and Hasrat (508) account for exactly 1000!
***********
This excerpt is taken from a post by Shri Shashi Hegde addressed to shankarjaikishan group on Yahoo
