ShiroKuro It's hard to summarize. You can check their web page: https://events.tonebase.co/in-person-classical-music-events/tonebase-la-intensive-2025
I attended the first of the two 4-day sessions.
High point for me was access to acoustic pianos in practice rooms. I love my N3 and VSTs, but acoustics are magic.
Second high point was the group master class with Garrick Ohlsson. Independently of Tonebase, I attended his recital the night before in Santa Barbara. We each got 8-10 minutes to play something and/or ask questions of him.
There were a number of lectures. I only attended Magdalena Baczewska's session on Bach Performance and Style. I skipped the classes on memory (couldn't remember to attend!), Singing for Non Singers, Composition Workshop, and Jazz Workshop. I also skipped the evening L.A. Phil concert presenting Gershwin's Concerto in F. (Needed sleep!)
Each participant had two lessons. Lessons were open-door. I sat in a brilliantly-focused lesson Magdalena gave on the Barcarolle.
Then there was a recital at the end. Probably 2/3 piano, 1/3 strings. Lasted two and a half hours (!) Included a couple of "ringers". One of Dominic's students, age 17, blasting through the last movement of the Rach Second Concerto with Dominic playing the orchestra secundo on the other piano. A pro/associate playing the enormous Bach-Busoni Chaconne. Then there were the rest of us amateurs with varying skill levels.