The group were turned down by Decca and the tape of Bowie singing a song called I Never Dreamed was never released.
Bowie quit the band in the following months and his career took off six years later with the release of Space Oddity.
The tape, which is expected to fetch £10,000, is part of a trove of memorabilia to be sold by former Konrads’ drummer David Hadfield, who also managed the band.
He unearthed it, while moving house in the 1990s, in the loft of his garage, in a bread basket that once belonged to his grandfather.
Bowie was the band’s saxophonist but it was decided that he should sing lead vocals for the tape.
“David had no inclination to become a singer at this point, his heart and mind were focused on becoming a world class saxophone player,” Mr Hadfield said.
“Our agent, Eric Easton, who also managed the Rolling Stones, asked us to do a demo so he could try and get us an audition at Decca.
“So in early 1963 I booked into RG Jones’ small studio in Morden. In preparation for the demo, David and our guitarist Neville Wills wrote two to three songs.
“We had decided that we would do a couple of guitar instrumentals and one original song. I chose I Never Dreamed as it was the strongest, the other two were a bit weak.
The demo tape was found by the band’s drummer in his loft in the 1990s (PA)
“I also decided that David was the best person to sing it and give the right interpretation. So this became the very first recording of David [Bowie] singing 55 years ago.”
Record company Decca rejected the demo tape, but did give the band an audition later that year, when Bowie sang backing vocals.
He left the band shortly after the audition, which also failed to get them signed, citing creative differences.
Letters, bills, booking forms, photographs and promotional sketches from Bowie’s early career will also be up for auction as part of the sale.
Auctioneer Paul Fairweather described the tape as a: “Significant recording, completely unique and of great historical interest, being the earliest studio recording of a fledgling musician who would go on to super stardom.”
The collection is set to go under the hammer in September at Omega Auctions, in Newton-le-Willows, Merseyside, in a music memorabilia sale.
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