Camp Curry was founded in 1899 as a less expensive alternative to hotels in Yosemite valley; David and Jennie Curry's tent-cabins continue to serve thousands of guests every year. In reference to David Curry's booming voice, and a nightly ritual known as the Fire Fall, a news release from 1910 reported "Every night they kindle a great campfire. The people gather about it, and as it dies down, some impromptu entertainment starts, or the whole camp overhears Mr. Curry's private conversations. And up on Glacier point, three thousand feet above, they kindle another fire, and as it dies down they throw it over the cliff. It makes a veritable cataract of flame and sparks--a beautiful sight. Mr. Curry thanks them at a distance of a mile."
The "impromptu entertainment" soon grew to polished stage productions, musical variety shows that would include classical music, skits, comic and popular songs and poetical readings. Early photos of these productions show that they were performed on the porch of the front office (now the lounge), and later on an outdoor amphitheater stage, next to a good sized bonfire. The photos also show pianos other than the one pictured above.
The earliest photo that I've been able to find of the Knabe piano (now at the Wawona) is this one, taken in the dance hall at Camp Curry--I haven't yet gotten a date on the photo or the construction of the building. I did notice that the pedal-lyre does not have the back braces that appear in the following photo from 1947 (and remained until 1990).