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Earlier it was Mohd. Rafi Ji & Lata Ji,
then it was Nusrat Ji
Now is Sant Sujan Singh Ji
once i went to a Gurudwara & a priest was playing live recording of a Shabad(hymn) Sung by Sant Sujan Singh Ji in Bilawal Raag. When i heard it i just stopped & asked myself Have you heard anything better than this in your whole life. The answer was No, not even 1/5 of it.
Sant Sujan Singh Ji CDs are available in the market but they are not even 5% of what i have heard..