7  Sensor unaffected by revolution (5)

 8  North Ashville is the place for music (9)

10 Sketchy boss with heart of stone had a tea party (6)

11 Two constants and a diagram inscribed on building (8)

12 Enjoying foolishly or saving (8)

13 Scallion relative overheard someone spill the beans (4)

15 Look into parsnips and mangoes for help going to sleep (7)

17 Mr. Rogers captured leaderless town and was unhappy (7)

20 Customer inside the bus errantly (4)

22 Shifted many tons and got opposites (8)

25 City explorer (8)

26 Headless Faust in spy powers (6)

27 Aide to help industrious insect (9)

28 Cooked meals in a crucible setting (5)

 2  Insurance capital filled with art for days (8)

 3  Mixed hair gel into Sir Walter's namesake (7)

 4  Weirdly, her trill was something exciting (8)

 5  Make mistake in pie for Frenchman (6)

 6  Changes opinions on somersaults (5)

 9  Opposed to part of mercantilism (4)

14 Missed one terribly in the city (3-6)

16 Trained cobra sat with gymnasts (8)

18 Reach improper spawning (8)

19 Capital gained from Bob Dylan singing (7)

21 Small apartment a gallery (6)

23 Dragged noisily to hopper (4)

24 Gumbo is everything! It contains a whole city (5)