The Fundamental Frequency of a Vibrating Guitar String Is Modeled $$f = \frac { 1 } { 2 L } \sqrt { \frac { T } { \mu } }$$

Essay

The fundamental frequency of a vibrating guitar string is modeled by the following equation: $$f = \frac { 1 } { 2 L } \sqrt { \frac { T } { \mu } }$$
where
$$\begin{array} { l } f = \text { vibration frequency in hertz } \\L = \text { length of string in meters } \\T = \text { string tension in newtons } \\\mu = \text { string density }\end{array}$$
What is the appropriate unit for $\mu$ if the preceding equation is to be homogeneous in units?