Psalms 89:1-4

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

Ethan : a wise man, an Ezrahite, in Solomons time,son of Zerah son of Judah; the father of Azariah,son of Zimmah, of Gershom of Levi; ancestor of Asaph; the father of Adaiah,son of Kishi (Merari Levi); a worship leader in David's time
(31° 22´, 35° 4´); (31° 22´, 35° 4´)

Ezrahite : a descendant of Ezrah

Maskil : a literary or musical term

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