There are two messages encoded simultaneously in the audio file.

Interpreting the file as Morse code (where in most cases, each letter starts at a different frequency, though the usual letter breaks are also present), the following characters mostly spelling out numbers are produced:

UNS.FUNFUNDSIEBZIGSIXTYTHREETWENTYSEVENSIXTEENFUNFUNDFUNFZIGHWV15SIXFORTYWWV2THREELQUATRES.-1TWOEIGHTEEN

Interpreting the frequencies as letters, starting with A at the 220 Hz A3 to to G at G4, then continuing with H at A4 and so on up to Z at E7 (2637 Hz) gives these letters:

LALOLISZTRIMSKYKORSAKOVSIBELIUSBRITTENBRAHMSHANDELELGARDVORAKWAGNERCHOPINDEBUSSYPDQBACHSHOSTAKOVICHGRIEG

The numbers are opus numbers, and the letters spell out names of composers. These should be paired in the order given and the titles of these works should be looked up (in the language corresponding to the number, where possible).

Composer	Opus Number	Language	Title	Initial
Lalo	1	French	fantasie Originale	F
Liszt	S.75	German	Uber allen Gipfeln ist Ruh	U
Rimsky-Korsakov	63	English	Neapolitan Song	N
Sibelius	27	English	King Christian II	K
Britten	16	English	Young Apollo	Y
Brahms	55	German	Triumphlied	T
Handel	HWV 15	-	Otto, King of Germany (Ottone)	O
Elgar	6	English	Wind Quintets	W
Dvorak	40	English	Nocturne in B major	N
Wagner	WWV 2	-	Sonata in D minor	S
Chopin	3	English	Introduction and Polonaise Brillante in C major	I
Debussy	L 4	French	Nuits d'etoiles	N
P.D.Q. Bach	S.-1	-	Gross Concerto No. 2	G
Shostakovich	2	English	Eight Preludes	E
Grieg	18	English	Romances and Songs	R

Note: There are multiple catalogs of some composers' works, and the letters in the opus numbers distinguish these. Where no letters appear, the opus numbers assigned by composers are used. Composers were not always consistent and sometimes reused these numbers, but the puzzle attempts to avoid those cases.

The initial letters of the titles spell FUNKYTOWN SINGER. The song "Funkytown" by the band Lipps, Inc. was sung by CYNTHIA JOHNSON, who is the answer.

The inclusion of composer P.D.Q. Bach and the German number funfundfunfzig (55) are just meant to make you laugh.