The voices that I recall often are almost always singers from my days of listening to music. Since quite a few of them were inherited from the choices made by my parents, some were of earlier vintage. The latter were fortunately available on records of 78 and later on 33 RPM discs. They are now of course available in digital form and can be downloaded from the Internet.
Paul Robeson, Ella Fitzgerald, Satchmo Louis Armstrong, Frank Sinatra, Dean Martin, Doris Day, Elvis Presley, Pat Boone, The Everley Brothers etc all followed during a period when I went through exposure to Western music.
Subsequently, I got involved in Indian classical music and there has been no looking back since. I love to listen to the old voices of just a couple of singers, but the ones who are still alive and giving concerts occupy my attention whenever I feel the need. My favourites are, Bhimsen Joshi, Pandit Jasraj, Rajan and Saajan Mishra, The Gundecha Brothers, Gangubhai Hangal and Kishori Amonkar in the Hindustani stream and Balamurali Krishna and the Bombay sisters in the Carnatic stream.