At high dihedral angles, close to perpendicular orientation, the B 1 transitions are dominated by the HOMO→LUMO and the HOMO-1→LUMO+1 excitations with 79% contribution each to the electronic transitions at 80 o torsion. Though the MOs are helical at near-perpendicular torsion angles, helicity is insignificant in the transition density because the helical components of the MOs are opposite. Through the full range of dihedral angles it is the twisted orientation of the end-groups that is responsible for the magnetic transition dipole. We find that this is also the case for higher-lying excited states of tolane that are optically active; it seems they are all driven by the charge moving between the two terminal phenyl groups and therefore those transitions are thus not of particular interest for this study. The helical MOs of tolane do not contribute to its optical activity. It is yet to be said, if this result is general for all polyynic molecules or specific to tolane.