This is a hauntingly beautiful section of the first movement.
After the composer has devoted so many preceding measures to the key of A minor, he decides to travel at quick intervals through a series of different keys. Such fast-paced modulations occur primarily with the return of the crossed-hands portion of the piece, beginning in F# minor at double forte level. (FF) (measure 99)
But before we get to this intensified point, Beethoven re-introduces a Largo, following the SECOND ENDING, which draws on the opening broken chord ROLL. The harmonies through which he passes are quite mystical. (especially when a D Major rolled-out chord is followed by a diminished one starting on B#) The third and final rolled chord in F# evokes the gates of heaven opening. At this point, the player must experience a divine revelation so he can communicate it convincingly to the listener.
The same mysticism blankets a Recitative, measures 144-148; and 155-158 with a submerged sustain pedal which is in itself, an innovative harmonic event in a Classical period sonata.
In fact, the “Tempest” is a ground-breaking composition just because the composer explores new tonal and harmonic regions while expanding beyond conservative form boundaries.
My video instruction elaborates upon this commentary:
Part ONE: Beethoven Tempest Sonata in D minor
Part TWO Instruction
Part THREE Instruction
Part FOUR Instruction