  I shall present a rather pedagogical discussion of the transversity
distributions in the quark-parton model and, in particular, the role of
perturbative QCD corrections. Among the topics I shall discuss are: LO and NLO
evolution, the Soffer bound and so-called K factors in the Drell-Yan process.
The main conclusion will be that, compared to unpolarised or even
longitudinally polarised hadron scattering, the case of transverse spin should
actually provide a far clearer window onto the workings of QCD and the
interplay with the quark-parton model.
