Cryptic crossword No 4,081

Across

1. One enjoying High Society or On the Town? (3,6)
2. Up in the air, temperature dropped around zero - chilly! (5)
3. Flash associate of A. Lloyd Webber (5)
4. Composer heard extract from song, maybe part of a cycle (9)
5. Polish chap leaving heart in Białystok and becoming prominent (8)
6. Tailor originally sewed up rough clothes (6)
7. Frank invitation from handsome, entertaining fellow in my company? (4,3,4,2)
8. A finale including tenor duet - listen! (6)
9. Australian party welcomes radical, a loyal companion? (8)
10. Get naked: Zorro's top layer's first to be removed here (5,4)
11. Obscure request requiring intervention of Foreign Office (5)
12. Reclining in an aeroplane, perhaps, dropping off in the end (5)
13. O new hell! A wretched overcommercialized celebration (9)

Down

1. Flawed character with no heart falsely imprisoning Zorro (4-4)
2. Ardour leads to fatalities, in Romeo’s experience (4)
3. Toxic substance supplied by criminal on the lam (8)
4. Weight lifter rushed in competitive event initially (5)
5. Front section to rear of cockpit area under canopy (6)
6. Sustainable energy endlessly renewed (5)
7. What flows in West Asia’s Tigris-Euphrates region, primarily? (5)
8. Yes, we all strangely like a furtive person (8)
9. I deform and I recast (8)
10. Maiden speech's opening made falteringly by Liberal (6)
11. Aerodynamic force working paper kite (6)
12. Passionate suitor ridicules trousers (6)
13. Soviet fighter plane gaining height and power (5)
14. Puritans with no right to become gluttons (4)
15. Punch boxer's head near to the ground (4)
16. Perplex philosopher not entirely comprehending Latin (6)
17. Spread wings in ether, head first (6)
18. Impudence beginning to get to everyone (4)