Macro for picking random entry from array

src/music.c

@@ -695,7 +695,7 @@ do_improvisation(struct obj* instr)
             /* TODO maybe: sound effects for these riffs */
             You("%s %s.",
                 rn2(2) ? "butcher" : rn2(2) ? "manage" : "pull off",
-                an(beats[rn2(SIZE(beats))]));
+                an(ROLL_FROM(beats)));
             Hero_playnotes(obj_to_instr(&itmp), improvisation, 50);
         }
         awaken_monsters(u.ulevel * (mundane ? 5 : 40));