I learned at school that Claude Montal was the one who invented the sostenuto, but according to Wikipedia:<br>-----------<br>The <b style="color: black; background-color: rgb(255, 255, 102);">sostenuto</b> was first shown at the
<a href="http://en.wikipedia.org/w/index.php?title=Paris_Exhibition&action=edit" class="new" title="Paris Exhibition">Paris Exhibition</a> of <a href="http://en.wikipedia.org/wiki/1844" title="1844">1844</a>, by <a href="http://en.wikipedia.org/w/index.php?title=Boisselot_and_Sons&action=edit" class="new" title="Boisselot and Sons">
<b style="color: black; background-color: rgb(255, 153, 153);">Boisselot</b> and Sons</a>, a Marseille company. French piano builders <a href="http://en.wikipedia.org/w/index.php?title=Alexandre_Francois_Debain&action=edit" class="new" title="Alexandre Francois Debain">
Alexandre Francois Debain</a> and <a href="http://en.wikipedia.org/w/index.php?title=Claude_Montal&action=edit" class="new" title="Claude Montal">Claude <b style="color: black; background-color: rgb(255, 102, 255);">Montal
</b></a> built <b style="color: black; background-color: rgb(255, 255, 102);">sostenuto</b> mechanisms in <a href="http://en.wikipedia.org/wiki/1860" title="1860">1860</a>, and <a href="http://en.wikipedia.org/wiki/1862" title="1862">
1862</a>, respectively. These innovative efforts did not immediately catch on with other piano builders. In <a href="http://en.wikipedia.org/wiki/1874" title="1874">1874</a>, <a href="http://en.wikipedia.org/w/index.php?title=Albert_Steinway&action=edit" class="new" title="Albert Steinway">
Albert Steinway</a> perfected and patented the <b style="color: black; background-color: rgb(255, 255, 102);">sostenuto</b> <b style="color: black; background-color: rgb(160, 255, 255);">pedal</b>.<br>-----------<br><br>As far as I know, the sostenuto pedal was not so common in European (and Japanese) pianos even in 1970's.
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