First off, I am an absolute beginner when it comes to audio software and processing in general, so apologies in advance for any misused or incorrect terminology.
I would like to take a song that consists of only one instrument (piano) and separate that song into two or more tracks, where each track contains the notes from different frequencies. Consider the song Numb, by Eydis Evensen. At timestamp 1:17, you can hear a note played from a relatively high pitch, followed by several notes played at a lower pitch. I would like to separate the higher and lower pitch notes into two tracks.
More Details and Context
Filtering by Frequency
I am working on creating sound-driven animations in blender and recently found this tutorial showing how to do such a thing. In the tutorial, the narrator identifies frequencies of various instruments and separates the track by these frequencies using a bandpass filter (starting at 14:25). Replicating this workflow did not produce good results for Numb, I am not sure if I was not identifying the right frequencies and just need more practice doing so, or if the notes in the song had such varying frequencies that they could be separated through this workflow. I suspected the latter, and went down the rabbit hole of converting an audio file to MIDI.
Also worth mentioning - the audacity workflow shown in the tutorial above is slightly outdated. I was having trouble correlating this workflow in the current version of audacity and decided to give Reaper a shot (which I think is a great program, I think a bit more intuitive than audacity). I tried following the workflows like in this video, but unfortunately was still not getting good results.
MIDI Rabbit Hole
Back to MIDI tracks. Before starting this task I was vaguely aware of MIDI tracks and what they are since I had encountered them for some other sound-driven animation work I looked into a while back. I tried finding a way to convert the song to a MIDI track, and understand that is a more-than-complicated task in and of itself. After some digging, I found the following resources for converting to MIDI:
Although these are great resources, the second link is for recording live audio which I could not translate for an existing audio file. The first link does provide directions for using an audio file, but after fumbling around with it I did not get any good results. What I could manage were just short little blips scattered sporadically across the various notes, rather than well-defined notes (like the output of the second link). Again, not sure if this is due to my inexperience with the software or if the track itself cannot be manipulated so easily.
I see there are other MIDI conversion methods, like converting to MIDI in melodyne, shown in this video as well as the programming languages mentioned here. Before diving into these options I thought I should ask if the MIDI conversion route could even produce good results.
So, the main question I have is:
Is there a way to separate the relatively high pitch notes from the relatively low pitch notes in the song Numb, by Eydis Evensen into two different tracks? (The relatively high/low pitch notes are apparent at timestamp 1:17 of this song)
My attempts so far have made me think of a few other questions too:
- Is this possible with frequency filters? Do I need to practice this workflow more or are the notes in this song too indistinguishable to separate? I also understand that at some points in the song the high/low pitch notes are played simultaneously, so no problem if those can't be separated.
- Is converting this song to MIDI worthwhile? If so, which tools would be best to focus my time on learning?
I know there is a lot to unpack here, but I greatly appreciate any help and time spent on this.