Final answer:
The two axes of music on a Western musical score are Pitch and Time, which relate to the vertical placement of notes for pitch and horizontal placement for timing.
Step-by-step explanation:
The two "axes" or coordinates of music found in a Western musical score are Pitch and Time. Option 2: Pitch and Volume is incorrect because volume (dynamics) is represented differently on a score, and is not considered an axis. Option 3: Time and Key is partially correct but key is not an axis; instead, it provides context for the pitch. Option 1: Treble and Bass are clefs, not axes, and Option 4: Melody and Harmony describe musical concepts but are not axes either.
The correct axes represented on a musical score correspond to the pitch of the notes, which is determined by their vertical placement on the stave, and to time, represented by the horizontal spacing and the rhythm expressed by note values and rests. Combinations of musical notes of specific pitch and duration come together to create a piece of music.