From the clavichord to the modern piano

Since the youtube description has no additional information in it, for anyone wondering who this guy is and if the information he is presenting can be trusted, I did some digging:
https://www.davidschrader.net/about

Mr. Schrader is on the faculty of Roosevelt University, Chicago College of Performing Arts - Music Conservatory where he has taught both graduate and undergraduate courses since 1986. From 1993 through 1995 he directed the Collegium Musicum at Northwestern University. He has also taught at the Music Institute of Chicago (formerly know as The Music Center of the North Shore.) For 35 years, he was the organist of the Church of the Ascension (Chicago), whose liturgies commanded a national reputation for musical integrity.

Mr. Schrader received a Doctor of Music degree in organ from Indiana University as well as the coveted Performer's Certificate. He received a Bachelor of Music in piano and a Bachelor of Music in organ from the University of Colorado. His principal teachers have been Storm Bull, Abbey Simon, Oswald Ragatz, Anthony Newman and Everett Jay Hilty.

So he seems pretty dang legit.