(1) ANY sound recording NOT fixed in the US of A is under copyright
for, usually, fifty years (in some cases, the end of the fiftieth
year following its being "fixed" (Don't dare use that word where
Ecru can overhear me...?!).
(2) If the sound recording did NOT originate in the US of A, it is
presumably NOT affected by Sonny Bono's "ultimate copyright term"
legislation...?!
(3) OTOH, if the recording is a non-US reissue of a sound recording
fixed in the US of A, it DOES fall under the "Bono Act," and will
not be p.d. in the US of A until 1/1/2067...?!