Johann Sebastian Bach - Orgelbüchlein ("Little organ book")
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http://www.backupmyfiles.net/download.php?file=623JS_Bach-Orgelb%FCchlein.pdf(en el link, buscar la frase "Download File Now" abajo de todo )
"an unfinished collection of 45 short chorale preludes that demonstrate compositional techniques in the setting of chorale tunes"
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