Products
PSR-E373 is a 61-key, standard model of Portable Keyboard for those who touch keyboard instrument for the first time, or even for players for performance ...
https://asia-latinamerica-mea.yamaha.com/en/products/musical_instruments/keyboards/portable_keyboards/psr-e373/index.html
Length and Style · Keys and Chords for Sight Playing, Accompaniment(Grades 10-8), Improvisation (Grades 7,6) and Hearing.
https://asia-latinamerica-mea.yamaha.com/en/education/yamaha_music_school/ymes/grade/student_grade/piano/10-6/index.html