Concerto no. 3 in D minor by JS Bach

"Concerto in D minor" is a great piece. It amazes me every time I hear it how many varied tonal colors an organ can achieve and yet how very purely pianistic it can sound at the same time. The piece begins with an orchestral section that sounds like a contrasting period with a cadential extension at the end. The first phrase seems to end on a half cadence while the second phrase ends on a perfect cadence. The organ enters for a section twice as long as the orchestral section in length. This makes me think it is a contrasting double period. At the end of the last phrase, there is a sequence that goes up by half step. Following these periods there is a new section with another set of melodic material. The piece is either in a very fast 4/4 time or cut time. This adds to the frenzied excitement. I think the most enchanting aspect of this piece is that the music is played in minor while the tempo and rhythm are in quick and dance-like intervals. This seems to create an irony since fast, upbeat music is generally in major while we associate slow, chromatic works with minor. I love how the opposition of this fact leaves a mesmerizing theme running through the listener's head all day long.