text: The fact that Brahms 's Symphony No. 1 is in C minor contributed to it being nicknamed `` Beethoven 's Tenth '' ( Beethoven 's actual unfinished Symphony No. 10 in E flat major may have had a significant central C minor section in the first movement ) .
simplified: The fact that Brahms 's Symphony No. 1 is also in C minor helped it get its nickname as `` Beethoven 's Tenth '' ( Beethoven 's actual unfinished Symphony No. 10 in E flat major may have had a significant central C minor section in the first movement ) .