Lacrimosa - from Requiem by Mozart, his last composition. Only the first 8 bars were by Mozart.

Mozart’s "Lacrimosa" from the Requiem in D minor stands as a testament to his unparalleled genius in creating music that deeply resonates with the human experience. Despite being unfinished by Mozart himself, the movement remains a powerful and moving expression of grief and contemplation, encapsulating the timeless beauty and emotional depth of his music. Its significance in the choral and orchestral repertoire continues to endure, captivating performers and listeners alike with its profound sense of sorrow and sublime beauty.

In bar one last beat, the C is an implied #9 on A7, a masterly use of harmony to evoke the haunting sadness it is conveying.