It could have been just a photo op but perhaps Sargent was in fact trying to heal the suffering of Galway through song. Even cryptosporidium is no match for Greens With Guitars.

Musical healing is nothing new. The ancient Greeks knew about it (along with everything else) and, in the 16th century, mental-health experts thought music and dancing were critical to the treatment of mental illness, including melancholia. But anyone who has ever sang into their hairbrush and jumped around their room to Boyzone could've told you that music makes you happier.

It is also supposed to make you smarter. Don Campbell's book on the so-called Mozart Effect tricked thousands into thinking they could create little Einsteins just by playing piano concerti to their kids instead of the Sesame Street soundtrack. Alas, the effect of Wolfgang Amadeus's tunes on your temporal lobe are at best short term.

If Sargent really wanted to learn about healing through the power of song, he should have gotten himself and his guitar down to the Irish World Academy of Music and Dance in Limerick, where you can study for a two-year masters degree in music therapy.

"The music can be the means by which the client communicates feelings and experiences, " says Dr Jane Edwards, course director. They do this by "playing improvised music made up spontaneously in the moment between the therapist and patient or through such interactions as singing songs or writing music together".

Music is also being used as a form of therapy in many hospitals and hospices. It helps motor skills, social interaction and cognitive development, apparently. So maybe music does make you smarter . . .

but did it make you Greener?