Spencer Davis has died at the age of 81, and one of Elton's bandmates has paid tribute on his Facebook page.
Nigel Olsson called Spencer ''a true legend in the music industry.''
He added: ''I had the honour in the late '60s of being part of the Spencer Davis Group, and will always have him in my heart.
''A true gentleman always.
''Thank you dear boy for inspiring me to believe in myself and live my dreams to full capacity.''
Before teaming up with Elton, Nigel and the late Dee Murray were members of the Spencer Davis Group.
The Welsh guitarist had been treated for pneumonia and was in hospital. He is survived by his longtime partner and three adult children.