Just some quick thoughts:
1. Examining groove width and geometry under a microscope can
probably identify whether the disc was recorded acoustically
or electrically. This gives you a very rough cut-off of the
mid-to-late 1920s as the transition from acoustic to electric
was taking place.
2. A 4 cm fragment taken from the center of the disc where the
groove velocity would be slowest, would give you a 81 msec
sound fragment. At the edge of the disc, that 4 cm fragment
turns into a 41 msec sound fragment. I don't think you could
identify much from that.
3. No database of 78 rpm disc chemistry exists to my knowledge,
and it would be costly to build and operate because of the
instrumentation needed to analyze the fragments. But that
might be another path of investigation. I don't know if, let
alone how, the disc composition varied by manufacturer over
time.
4. Groove wear as observed under a microscope would tell you
if the disc was popular with the listener. The wear pattern
would also tell you if the listener was fastidious about
replacing styli regularly. In all, I think the only real
judgment you could make is if the listener liked that
particular disc. If all the discs were well worn, you might
be able to make other judgments - like that household listened
to music regularly.
I'll keep noodling on this question...
Eric Jacobs
The Audio Archive, Inc.
tel: 408.221.2128
fax: 408.549.9867
mailto:EricJ@xxxxxxxxxxxxxxxxxxx
-----Original Message-----
From: Association for Recorded Sound Discussion List
[mailto:ARSCLIST@xxxxxxx]On Behalf Of Oliver Mueller-Heubach
Sent: Monday, October 15, 2007 9:16 AM
To: ARSCLIST@xxxxxxxxxxxx
Subject: [ARSCLIST] 78 rpm fragments in archaeological contexts
Hello
I’m an historical archaeology Ph.D. student at the College of William and Mary
working on a paper for a material culture class. My goal is to create a
methodology for using the 78 rpm record fragments commonly found on early
20th century archaeological sites to help look at issues of class, race, ethnicity,
and gender. Since it is very rare to find fragments with portions of the label
surviving, the paper will focus on things like material composition, thickness,
edge-type, etc. I would like to produce a typology of characteristics that might
correlate with different economy and deluxe labels, series, and date ranges.
Ideally, I would like to find a way to read the grooves on the fragments to help
identify the type of music. Unfortunately, the fragments found are generally
only1-4 cm. in size. The analog method that occurs to me is to cut a section out
of a poor condition, non-archaeological 78 with a Dremel-type tool and then
patch in the fragment and play, listening for the deviation from the surrounding
song. This would probably prove difficult in terms of aligning grooves and
identifying such a minute section of music, but I will be giving it a try. I have
seen some reports of digital scanning and reconstruction of broken 78s and
cylinders, but apparently these techniques are being applied to restore mostly
complete recordings. Is there a way that single record fragments could be read
digitally to interpret the style of music (or even compare it to graphs generated
by the practice of re-mastering old recordings and thus match the actual song)?
I realize this is probably a long shot, but if there is a chance, it would be a great
archaeological tool.
Thanks in advance
Oliver Mueller-Heubach