Hi Kevin,

Thank you for contacting Mearto with your appraisal inquiry.
The condition and lack of a serial number or maker's name keep the value on this piano low; currently about $200-300. As to the issue of provenance, the ultimate provenance is to have an instrument that was OWNED by an artist (significance of the artist directly relates to value, with some artists adding more value than others) taking slight precedence over instruments that were just PLAYED by an artiest. With the artists names provided, provenance would add an additional $2,500-4,500
This appraisal is conditional pending documentation and a clearer understanding of the condition of this piano.
Based on the photos and information provided, and subject to examination, this is:

An antique Edwardian upright piano
unattributed maker, early 20th Century
The rectangular back with outset rounded-facade sides over a standard keyboard raised on turned tapering reeded legs. Presumably unmarked.
6 feet wide, 2 feet deep
CONDITION: Some keys stuck, cosmetically this piano has scratches. Client attests this piano "needs work" but doesn't specify.
PROVENANCE: owned by Art Laboe and in his recording studio. Used in recording sessions by The Wrecking Crew, Carole King, Captain Beefheart, The Monkees and Harry Nilsson.
$ 200-300*
*represents a fair-market value for auction purposes; retail or asking price may vary.

Please let us know if you have additional items to appraise, or questions/concerns, and thank you again for using Mearto.
~ Delia