The First Acrostic Psalm
Psalms 9.1 - 20
Muth-labben probably refers to the tune to which the words of Psalm 9 were set. Translated this mean "With my whole heart!"
Psalm chapter nine is the first of the Acrostic or Alphabetical Psalms, of which there are nine (9; 10; 25; 34; 35; 111; 112; 119; 145.) Psalm 119 is perhaps the most remarkable specimen of this acrostic style of composition. Proverbs 31, and Lamentations 1; 2; 3; 4 present the same acrostic character.
An acrostic is a poem or other form of writing in which the first letter, syllable or word of each line, paragraph or recurring feature in the test spells out a word or a message.