When I was a kid in the late 70s and early 80s, I used to hear this
strange, eerie tune on the radio late at night. What WAS it?

I used to listen to this radio program called The CBS Radio Mystery
Theatre (Twilight Zone-like radio plays). The station I listened to it
on was WBBM in Chicago. After I'd been listening for about a year, I
started getting this uneasy feeling at certain times during the
broadcast, but I couldn't figure out why.

Then I realized what it was: there was a weird little tune playing
over-and-over again in the background, so quiet that it was just on
the edge of my consciousness. Every night, this tune would start
playing, but always at different times. Quiet as it was, after I
became aware of it, I couldn't NOT hear it. Sometimes I would drift
off to sleep during the show, and then suddenly snap awake when that
tune started playing. When I asked other people to listen to it, they
generally couldn't hear it unless I taped the show and played it over
and over again. Then they'd say, "oh yeah! I hear it now."

Now, this wasn't background music to the radio drama, because
sometimes I would hear it WHILE the real background music was playing.
Anyway, it wasn't appropriate to the stories. Actually, the music may
have had nothing to do with the CBS Mystery Theatre. I might have been
something WBBM was playing, and it might have played during other
programs too, but at that time, the Mystery Theatre was the only thing
I listened to on that station.

It occurred to me that it might be coming from another station close
by, and that the sound might be bleeding into WBBM. So I spend hours
subtly adjusting the radio dial, but it was pretty clear to me that
the tune was coming from WBBM.

It was a short tune that repeated about 10 times and then stopped. It
was very quiet, and it sounded like it was being played on the very
high keys of a piano (no chords, just a tapped out melody) or maybe
even a child's xylophone.

That tune will be stuck in my head forever! I made an mp3 of myself
whistling it. It's really bad in quality, because my mic is old and
broken, but all of the crackling will simulate the way I used to hear
it, because WBBM didn't come through all that clearly.

http://www.grumblebee.com/mystery.mp3

This is one of the biggest mysteries of my life. If anyone can clear
it up, I'll be eternally grateful!

From the description it was most likely subliminal programming signals
piggy-backing on the carrier waves.

mgeduld-ga:

On a related note, you can listen to some archived episodes of Radio
Mystery Theater through some fan sites, such as:

http://www.jessthemess.net/cbsrmt/

If you have the time, listen to a few episodes, and see if you can
hear that sound (perhaps the easiest way is to simply start the audio
stream in the background, then wait to see if the hair on the back of
your neck stands up part-way through the episode).

Regards,

aht-ga
Google Answers Researcher

Thanks. Actually, I have ALL of the episodes in mp3 form. I bought
them from someone on ebay. And while I haven't listened to all of them
yet (there are about 1400), I've listened to a bunch of them and have
yet to hear the tune. I suspect it was a WBBM phenomenon, having
nothing to do with the Mystery Theatre. I heard it during the Mystery
Theatre because that was the only program I listened to on that
station.

mgeduld-ga:

Yes, after I posted that comment I thought again about what you
described, and realized that you'd stated that you did NOT think it
was part of RMT, that it was a WBBM phenomenon instead.

I then tried to look for any information about the WBBM station tones,
but was not able to find anything. I too remember listening to
late-night mysteries on the radio while I was falling asleep, and
typically the radio station would play their tones at some point in
the broadcast. This was separate from their 'top of the hour' tones.

Perhaps your best path to solving this problem is to contact the
current WBBM, and see if they can tell you (or put you in touch with a
retired station technician/engineer who can).

Good luck!

aht-ga

Here's WBBM's contact form, if you haven't already found it:

http://www.wbbm780.com/asp/ContactUs.asp

I suggest using the "Comments to the engineers" option. The 70's/80's
may have been when one of them started at the station... and something
like station identification tones would have been the type of
grunt-work that they would have started with, especially for a
late-night program.

Normally, for a question such as this, I would pursue it for you;
however, in this particular case, there will be a need for some
dialogue between you and the engineers at WBBM, so no value in having
me as the middle-person!

Good luck!

aht-ga

Dear mgeduld:

I asked my father who has been a radio engineer for 65 years (no
kidding).  He has worked in everything from the earliest days of AM
through to and including Internet web casting.  Here is his answer
(note that he assumes you were listening on AM):

"Re: WBBM...WBBM was and is also an FM Stereo station...What he heard
probably was the testing of the FM sub-carrier bleeding into their AM
equipment...He should also talk to WBBM's Chief Engineer."

A sub-carrier is a special little secret frequency the FCC allows FM
stations to broadcast along with their main FM signal for purposes of
carrying, e.g., background music ("Muzak").  So, you could put up a
special FM radio in a business and tune it to the "secret" FM
sub-carrier frequency and listen to commercial-free background music
for a fee.  If WBBM was testing the FM sub-carrier with this special
little series of tones, that tone sequence could have bled over into
the AM signal.

I have been around radio stations my whole life and this answer makes
sense to me.  I would now check with WBBM is you haven't already.  Let
me know what you find out!

ipfan