# For the chief musician

"This is for the director of music to use in worship"

# set to Al Tashheth

This probably tells what musical style or tune to use when singing the psalm.

# A psalm of David

Possible meanings are 1) David wrote the psalm or 2) the psalm is about David or 3) the psalm is in the style of David's psalms.

# A michtam

The meaning of the word "michtam" is uncertain. You may use the word "psalm" instead. 

# set me on high

"put me in a safe place" 

# rise up against me

"attack me"