Hi Carole
16A. chant = monotonous song
brief conversation = chat
new opening = n (opening means 'starting' letter of the word 'new')
26A. website = homepage
where to take up spinning = web site
35A. nutshell = a hard case to crack
maniac's = nuts
nightmare = hell
68A. need = require
previously named = nee
five hundred =D (in roman numerals)
Good luck Carole, hope this helps.
Regards, Butterfly