While it is good that sexual harassment is being added to the 2010 Equality Act this year, it will not cover volunteers (The world has changed. So why do businessmen still think they can harass women at work parties?, 4 April). In fact, the Equality Act only covers employees. Volunteers can be discriminated against or sexually harassed with no protection. It’s time they were included in the act. Lorna Henderson Newcastle upon Tyne Alexis Petridis says that “it is hard to think of another Turner prize-winning artist whose work is so bound up with pop” than Wolfgang Tillmans (‘Blue Monday is one of the 20th century’s greatest artworks’: Wolfgang Tillmans on swapping his camera for a microphone, 4 April). How about Jeremy Deller and Mark Leckey with, respectively, Acid Brass and Fiorucci Made Me Hardcore among their pop-related works? Bryan Biggs Liverpool Re sound effects (Letters, 10 April), I remember a performance of David Rudkin’s play Afore Night Come that featured a gruesome beheading – at which point I thought someone was slow-handclapping, which was odd. I looked round and found that they were trying to revive a member of the audience who had fainted. Tony Burton Stroud, Gloucestershire Re your article (Colombians told to shower with a partner as drought hits capital water supplies, 12 April), won’t the effect be that they will spend longer in the shower? Alan Frost Salisbury The rapper Akon says: “I don’t think anyone can tell you they weren’t a Michael Jackson fan at his peak” (Honest playlist, 15 April). I can. Michael Fuller Harpenden, Hertfordshire