Cryptic crossword No 3,780

Across

1. Pierce and Richard left in class (7)
2. Raise covering letters to back Congress (10)
3. First bit of animation switched for appeal (10)
4. Blatant flashing! (7)
5. Boy good about Royal Academy at first forcibly testing musical ability (9)
6. Fanfare when singer holds youth party (11)
7. Robbing banks, gunman skids, dropping papers, and exposes himself (7)
8. Evolutionist drawing most of Tousled Cardinal (9)
9. Actor following Polish band to country house retreat? (11)
10. Schedule turn (4)
11. Dismal Scottish courier loses coat (5)
12. Finally, let's eat wagyu breed beefcake (4)
13. Simple Trevor mostly withdrawn (5)
14. Cracked lone pun (or one of nine?) (7)

Down

1. Sleep around? Reckless! (5)
2. Vessels are from earliest generation (7,8)
3. Biomass European sampled for rubber (7)
4. A sign to start typing fast? (6)
5. Girl thievin', you say? Wrong! (8)
6. Henry's leaving unfinished dice game for no-good Chinese banker (7)
7. In class, Aileen is very musical (5)
8. Italian grandma dead, said figure (7)
9. Spot progress in second childhood? (6)
10. Scully's partner exchanged first-hand snuff (6)
11. Friday night: Romeo starts off sex frenzies! (6)
12. Learning by doing test on one sail, stupidly lowering mass to the bottom? (15)
13. Moral code of president agreeing to marry? (7)
14. Safe to eat beef in broken tin with no cloudy coating? (3-5)