You're very close! The Quadrivium consisted of four subjects, but one of them is slightly different.

The four subjects of the Quadrivium were:

* Arithmetic: The study of numbers and their properties.

* Geometry: The study of shapes, sizes, and spaces.

* Music: The study of sound and its mathematical relationships.

* Astronomy: The study of celestial bodies and their movements.

So, while music and astronomy are part of the Quadrivium, geometry replaces what you mentioned.