Across:
   1. Grown this way? (5)
   4. He appealed to bluegrass fans, and to cows, appropriately (3 6)
   9. Tenure I arranged for circle of companions (7)
  10,22dn. Twistedly parrot (i.e. mock) famous star gazer (7 5)
  11. He might have played the best guitar parts in "Tommy", were song rewritten (3 10)
  13. On lake, our ice mostly firm, and a bit slippery for old magpie (3 8)
  17. Place that loves Samba as essential to three-piece bands (3)
  18. Demolish tea? (3)
  19. Taken back? Some stewardesses so personally taken back! (11)
  20. Injured emu carer, a calm career for a quiet achiever (6 7)
  25. To West Autralian, 'net naturally uses this device (7)
  26. What one thought of onion wisely kept quiet by one! (7)
  27. Homes were getting rebuilt in uncertain location (9)
  28. Trout off at teacher (5)
Down:
   1. Vows we reel off as creatures prone to change (10)
   2. Has to reform vows (5)
   3. Role doing transport? (9)
   4. Dreadful first sore lingered (5)
   5. Storage of metals ruined roads (9)
   6. David who has set many crosswords and written strange tales (5)
   7. Seaside infrastructure cleverly hid sprays (9)
   8. Cheekiness essentially turned into successful trademark (4)
  12. U.N. error, and disaster for bird (10)
  14. Demand I maul mutt boisterously (9)
  15. Punctuate "hate'n'hype" with a different approach? (9)
  16. Plant used to wrap limb with iodine (9)
  21. Update on little Frankfurter turning up with iodine deficiency (5)
  22. see 10 across
  23. Kick out mischievous civet (5)
  24. "Sub" (as subwoofer) provides it (4)