Psalms 55:1

David : a son of Jesse of Judah; king of Israel,son of Jesse of Judah; king of Israel

Maskil : a literary or musical term

Psalms 4:1-8

David : a son of Jesse of Judah; king of Israel,son of Jesse of Judah; king of Israel

Selah : a musical notation for crescendo or emphasis by action (IBD)
(30° 19´, 35° 27´)