Edvard Grieg's 'In the Hall of the Mountain King'
This piece is famous for its prestissimo finale which gets increasingly hectic. It was originally composed as incidental music for Henrik Ibsen's play, Peer Gynt. The theme is also notable for its appearance as one of the first sonic leitmotifs in cinema (and also one of the first instances of diegetic music--that is, music that appears because it is an explicit part of the narrative), appearing as the whistled sound-tag of the villain in German director Fritz Lang's M.
Louis Armstrong and Ella Fitzgerald's performance of 'Summertime,' written by George Gershwin
Rock and pop:
The Kinks' 'Waterloo Sunset'
Have a great day all! Hope your weeks are off to a fantastic start!