In this paper, we study tridiagonal random matrix models related to the classical β-ensembles (Gaussian, Laguerre, and Jacobi) in high-temperature regime, i.e., when size N of tends infinity with constraint that βN = 2 α constant, > 0. We call these ensembles Gaussian, Jacobi α-ensembles, prove convergence their empirical spectral distributions mean densities states, compute them explicitly....