What does "Maskil" in the heading of a psalm mean?

This study suggests that the word maśkll in the heading of a psalm is a musical instruction that denotes a specific responsive mode of performance defined as complex antiphony because it involves the gathering of distant segments of the text through a dialogue between choirs, each singing a different section of the edited song. This premise is supported by the use of pi'el śkl to express an unusual (crossed) bonding (Gen. 48:14), testimonies in Chronicles about difficulties in the execution of this mode of performance, the mention of śekel/maśkll in psalms specifically designed for complex antiphony, and the intellectual effort required to apprehend the meaning that emerges from such a dialogic mixing of claims, itself echoed by other uses of the Semitic root śkl.