Evolutionary tracks for models with an initial mass between 0.8 and 120 M_⊙ with a mass fraction of heavy element Z = 0.006. The colors along the tracks give an indication of the surface nitrogen to hydrogen ratios. The gray band shows the Cepheid instability strip. Left panel: nonrotating models. Right panel: rotating models with υ_ini/υ_crit = 0.4. The initial equatorial velocity on the ZAMS, as well as the time averaged velocity on the MS is given in the second and third column of Table A.1.