If the grid were a TIMEPIECE (13/12), the six perimetric words (GRANITE, LIMESTONE, SERPENTINE, GREYWACKE, DALRADIAN and HORNFELS) might collectively suggest ‘Rock Around the Clock’, which song was RECORDED (22) SIXTY (19) years ago, on 12th April 1954, by Bill Haley & His Comets. HALEY (eighth row) was to be shaded.
 
First prize David Peachell, Bexley, Kent
Runners-up J.E. Green, St Albans, Herts; E.C. Wightman, Menston, Ilkley, W. Yorks