organ
1. Also called pipe organ. a musical instrument …
4. Biology. a grouping of tissues …
5. penis.
Church musicians with a certain sense of humour, or people with a certain sense of humour who know church musicians, are prone to making jokes about organs. At one time it was possible to buy t-shirts or windcheaters with the words ‘Bach’s organ works’ on the front and ‘and so does mine’ on the back. (Note: JS Bach and his two successive wives produced 20 children between them.)
It is possible for writers from earlier times to make innocent innuendo. During his visits to England, Felix Mendelssohn met and became quite friendly with Queen Victoria and Prince Albert. On one visit, Mendelssohn wrote (in a diary or letter):
Joking apart, Prince Albert asked me to go to him on Saturday at two o’clock so that I may try his organ.
ed Derek Watson, The Wordsworth Dictionary of Musical Quotations