A steel wire (e.g., a piano wire) for use in a stringed musical instrument
is designed to have a specific chemical composition in which phosphorus
content ranges from 0.015 weight percent to 0.050 weight percent, wherein
the total decarburized layer depth of a decarburized layer formed on the
surface, which is subjected to decarburized depth measurement using a
microscope method as defined in the Japanese Industrial Standard JIS G
0588, is reduced to 2 .mu.m or less. Other chemical substances included
in the chemical composition of the steel wire are preferably defined in
the standard JIS G 3502 regarding chemical compositions of piano wires.
In manufacturing, a rolled steel material is subjected to wire drawing
and patenting under prescribed conditions, wherein the sound quality
realized by the steel wire installed in a stringed musical instrument can
be noticeably improved by adopting both chemical composition control and
total decarburized layer depth control.