What's not as well known is that Bach is author of neither the basic melody nor the words. The composer merely incorporated into his composition (with some significant adaptation) what was already a familiar hymn called O Haupt voll Blut und Wunden ("O Head Full of Blood and Wounds"). The music, which dates from about the year 1600, was composed by Hans Leo Hassler.
The Inner Struggle: Palm Sunday and Passion Sunday
We gain something, however, from seeing the joyful palm-waving crowd welcoming Jesus and the angry crowd demanding his death in the same liturgy. We see a reflection in today's mass of the struggle within each of us between the desire for salvation and the allure of sin.