 Roger Keith " Syd " Barrett ( 6 January 1946 – 7 July 2006 ) was an English musician , composer , singer , songwriter , and painter . Best known as a founder member of the band Pink Floyd , Barrett was the lead singer , guitarist and principal songwriter in its early years and is credited with naming the band . Barrett was excluded from Pink Floyd in April 1968 after David Gilmour took over as their new guitarist , and was briefly hospitalised amid speculation of mental illness . 
