How do you calculate wave speed along a vibrating string?

On an ideally elastic and homogeneus string, the square of the speed is the tension upon wich the string is subjected, divided by its linear mass density (mass per unit lenght). That is v^2 = T / (M/L), where v is the wave speed, T the tension, M the string's mass and L its length, so M/L comes to be the linear mass density (for an homogeneous string).