{"id":1472,"date":"2020-12-22T14:12:28","date_gmt":"2020-12-22T21:12:28","guid":{"rendered":"http:\/\/www.timsummers.org\/?p=1472"},"modified":"2020-12-30T02:19:37","modified_gmt":"2020-12-30T09:19:37","slug":"midi-harmony","status":"publish","type":"post","link":"http:\/\/www.timsummers.org\/?p=1472","title":{"rendered":"midi => harmony"},"content":{"rendered":"\n

harmonypartition<\/em> works simply and cleanly with MIDI files.<\/p>\n\n\n\n

Using the music2<\/em>1<\/a> package, harmonypartition<\/em> is able to analyze a MIDI file in exactly the same way it analyzes an audio file.<\/p>\n\n\n\n

Results from MIDI are cleaner than those from audio \u2013 though not necessarily better<\/em>, since resonance and continuity play such a key role in analysis, performance, and understanding. But MIDI is an important and stable reference in music notation, and provides invaluable information on many levels.<\/p>\n\n\n\n

analysing a MIDI file<\/h2>\n\n\n\n

Below is an analysis of the same progression as on the previous pages: vi-ii-V-I in C Major, from a MIDI file:<\/p>\n\n\n\n

bin_a, kpdve_a = pt_analyzeMIDI.analyze_notation_file(\"vi_ii_V_I.mid\", beats_per_slice=2)<\/code><\/pre>\n\n\n\n
This analysis (like all analyses in harmonypartition<\/em> yields two crucial pieces of information. The first is a binary ‘punch card’ of pitches. The second is an analysis of probable function. These can be seen below. First, in binary (with analysis given below):<\/p>\n\n\n\n
\"\"<\/figure>\n\n\n\n
Second, coded by proximity and most probable (or, more to the point, laziest possible) harmonic function:<\/p>\n\n\n\n
\"\"
harmonypartition<\/em> analysis, with  chords (large blocks) in C Major (bottom stripe)<\/figcaption><\/figure>\n\n\n\n
This analysis is very close to what derives from the Fourier analysis of a live performance of the same music, here played on a lightly out-of-tune piano:<\/p>\n\n\n\n
\"\"<\/figure>\n\n\n\n
vi-ii-V-I live on funky piano<\/figcaption><\/figure>\n\n\n\n
further examples: MAESTRO dataset<\/h2>\n\n\n\n
Then, to take a leap away from the vi-ii-V-I, here is a somewhat more sophisticated examples: Prelude and Fugue in A Minor, WTC II, BWV 889 (Johann Sebastian Bach), from the MAESTRO<\/a> dataset. First an analysis of the audio recording:<\/p>\n\n\n\n
\"\"
Audio\/Harmony analysis: Prelude and Fugue in A Minor, WTC II, BWV 889 (Johann Sebastian Bach) — using librosa<\/em> stft<\/figcaption><\/figure>\n\n\n\n
And here an analysis of the MIDI version of the same performance:<\/p>\n\n\n\n
\"\"
MIDI\/Harmony analysis: Prelude and Fugue in A Minor, WTC II, BWV 889 (Johann Sebastian Bach) — using music21<\/em> for chord extraction.<\/figcaption><\/figure>\n\n\n\n
These analyses could use some smoothing and statistical comparison, but all in all, it’s not bad for pure binary logic \u2013 which seems like a good, rooted place to have a meeting point.<\/p>\n","protected":false},"excerpt":{"rendered":"
harmonypartition works simply and cleanly with MIDI files. Using the music21 package, harmonypartition is able to analyze a MIDI file in exactly the same way it analyzes an audio file. Results from MIDI are cleaner than those from audio \u2013 though not necessarily better, since resonance and continuity play such a key role in analysis, […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[60],"tags":[],"aioseo_notices":[],"_links":{"self":[{"href":"http:\/\/www.timsummers.org\/index.php?rest_route=\/wp\/v2\/posts\/1472"}],"collection":[{"href":"http:\/\/www.timsummers.org\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.timsummers.org\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.timsummers.org\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/www.timsummers.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1472"}],"version-history":[{"count":13,"href":"http:\/\/www.timsummers.org\/index.php?rest_route=\/wp\/v2\/posts\/1472\/revisions"}],"predecessor-version":[{"id":1621,"href":"http:\/\/www.timsummers.org\/index.php?rest_route=\/wp\/v2\/posts\/1472\/revisions\/1621"}],"wp:attachment":[{"href":"http:\/\/www.timsummers.org\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1472"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.timsummers.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1472"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.timsummers.org\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1472"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}