The unnamed artist, who started sending intricate sculptures to cultural organisations across the city seven years ago, has thrown her weight behind the bid by St Mary's Music School to relocate to the Royal High School on Calton Hill.
Her latest work, which is around 37 centimetres tall, depicts a musician on stage surrounded by flying musical notes.
It features an excerpt from JK Rowling's first Harry Potter novel featuring Professor Dumbledore, which reads: "Ah music,' he said, wiping his eyes. 'A magic beyond all we do here.'"
The artist, whose identity is known by only a handful of people in the city, had previously pledged that a a 6 ft tall sculpture of a child hugging tree, which was delivered to the Edinburgh International Book Festival site, was her final work.
However she has decided to follow in the footsteps of the likes of violinist Nicola Benedetti, composer James MacMillan and author Alexander McCall Smith in backing the relocation bid.
The school has won planning permission to turn the old Royal High School into its new home, as well as a new concert hall, but its plans rely on developers behind a luxury hotel project pulling the plug on a long-term lease agreement with the city council. A public inquiry is about to get underway into the latest hotel scheme, which was rejected by councillors.
In a note to the music school, which is currently based in the city's west end, the artist said: "What makes a place, in this case a city, this city, special?
"The question of what we do with our buildings has to be key. It is no secret that I think the arts matter, the buildings as well as the contents.
“The Old Royal High School was designed and built with enlightenment and education in mind, with a hope for the future.
“As St Mary’s Music School, that legacy would continue. In the heart of the city, up on the hill, a centre of musical excellence would speak of the importance of music and music education to every child’s life."
Dr Kenneth Taylor, the school's headteacher, who unveiled the sculpture to pupils today, said: "Everyone at St Mary’s Music School is delighted that the anonymous sculptor has gifted us with an exquisite sculpture of a cellist and given her pledge of support for our proposed move to the Old Royal High.
"We're greatly encouraged by the support we have received from her, members of the public in Edinburgh and many high profile figures in the music and arts communities.
“St Mary’s Music School has always had outstanding pupils and teachers. Our learning and teaching would be further enhanced with the facilities which a truly outstanding building would offer."