I don't know whether it is exactly what you are looking for, but I like the NoteWorthy Composer. It's price is USD $49, but there is a free trail. There is no time limit on using the trail, but you can't save anything in the trail.
Here is a screenshot:
I have found the dinosaur: Impro-Visor. Here are my first experiences:
be sure to have a 32-bit Java VM at hand; to avoid undesirable interaction with my previous installation, I used a Portable JRE
to get rid of the Metal Look and Feel, you can add a line to impro-visor.vmoptions:
Music.SE has been trying to push for Lilypond support which has many of the features you have requested.
There is a lot of external support for Lilypond as shown by numerous third-party components, and there's definitely been some interesting integration done with MediaWiki where it not only displays the music, but also plays it.
Here's a simple example:
I tried different tools for this and my first choice has always been Guitar Pro for composing using pure chords. However, you are right about the sound quality. Of all the other tools I tried, GarageBand beats quite everything in matters of sound quality in my experience. Of course, GarageBand is quite a different tool than Guitar Pro but no composing tool ...
This is possible with MuseScore 2.
edit scores with everything mentioned before and a lot more
print scores and export as PDF, PNG and some others
export songs as WAV, MP3 and MID
works on Windows 10
is not a Windows store app
is free (GPL 2)
I would suggest taking a look at Denemo which seems to fit a lot of your requirements:
Music input from teh PC Keyboard, MIDI Controller or acoustically
Produces sheet music in various notations vial LilyPond to produce beautifully typeset sheet music.
Your music can produce prints, images and music files as well routing your music in real time to other ...
You will find a useful set of resources for Python at the Python In Music page. This includes tools for feature extraction from Audio files as well as for MIDI & Music XML processing.
For your specific task I suggest taking a look at music21 and it's documentation
It comes with a huge corpus of Music XML files and you can add your own from local or ...
If you prefer the GUI part in your question, I would recommend MuseScore. It is Open Source and has a Plugin System, so you may extend it to your needs. MuseScore is based on Qt.
However, if you are looking for an even more programmable approach, you should check LilyPond. This is kind of LaTeX for music notation.
I would suggest taking a look at LilyPond it is one of the best music typesetting packages available:
Free, Gratis & Open Source
Cross Platform Windows, Linux & OS-X
Includes multiple types of music notation from Gregorian Chants to full orchestration, including cording.
You can even find a recipe for creating a booklet at https://github.com/...
I would suggest taking a look at MoviePy which will let you combine video clips, images, text, soundtrack, etc. into a movie with whatever timings you need
Cross Platform including Windows & Linux
I know it's a bit old but I just came across this question :)
How about lilypond. It's cross-platform, (works on all versions of Windows as well). It's a text based music notation, can export to midi and pdf music sheet. Check it out for far more awesome features at http://lilypond.org.
tl;dr: Check out Finale Notepad
I'm a composer of classical music, and it sounds like you're looking at more pop-ish things, so take my advice with that caveat.
The big split in composing software is between Sibelius (which I think is better software by far) and Finale (which has a free version), so that's what I'd recommend to you. Both are expensive, but ...