V3.6.2 - All staves sound like piano

I do not see this as the issue. Regardless of the source of the initial input, the application should be operating in its own system under the auspices of its own architecture. If the Properties of a staff are assigned to, say, "Trumpet", then there is no way that the music should sound a "Trombone". The question is not, "What are the nuances of the input XML file?", but rather, "How can MuseScore display one instrument and play another?"

What this means is that the application is architected without consideration of WYSIWYG. The Properties widget is not coded to check its display, which is typical of software development: one hand not knowing what the other is doing. (Users have only the UI as the means of communicating with a computer, yet UI considerations are consistently the least attended-to aspects of software, even after 40 years after the advent of the micro-computer.)

Once the import has finished, no matter how flawed that input data is, there is no reason why the user cannot manually adjust the settings in the tool once the file has been saved to standard format. After that save, the data schema should now exist in MS just as if it were entered by hand - the input file is now of no consequence, operationally. Thus, if instrument mismatches occurred during import, then users should be able to easily reinstate these in the UI. The fact that we can't is wholly an issue of MS, not Sibelius or XML format, and the fact that this "bug" (a warm-fuzzy term smuggled into our parlance in place of its proper term: "failure") has existed for multiple releases now means that MS developers neither know nor care what causes it.

In my case here, MS recognized most of the staves in the original score and assigned similar if not exact labels to them as well as the voices I had originally assigned. I can understand if there was "confusion" on the import, however, and that now cleanup is required. Once I went into the Inpsector or the Mixer, however, this "default" Grand Piano you mention should have simply gone away once I manually assigned the instrument I wanted.

There is never ever a valid reason why a user interface displays one thing and executes another. Never. In our case here, if MS insists on performing piano when the user has selected a voice instrument, then the button dropdown should display "Piano" or render a detailed error message as to why this is happening and what the user can do to fix it. If the user cannot fix, then a bug report can be written up and the issue addressed, but at least the UI remains consistent and trustworthy.

The fact that the button dropdown continues to display the incorrect instrument and that there is no help from the application is completely the fault of the application, not the XML import.

Marc: The vocals in my score go back and forth between "Aahs" and "Oohs" and the upright bass toggles between plucked and bowed. I did not expect MS to necessarily pick up on this, but did expect that it would either a) simply default to the instrument that the score begins with, or b) allow me to make the changes manually. Neither of these occurred.

Still, when I've provided examples of the Properties from the screen caps, I have taken them right from the part of the music in question, not the score as a whole. I've attached a snip of the score to this post where the vocals come in for the first time. You can see the blue staff label I right-clicked on to get the Properties dialog to appear. This is what I clicked on to get the snip I sent in my previous note. This is exactly what I get when I click on the precise note (also highlighted in blue).

This tells me that this single note - not just the part, not just the entire score, but the note itself, is incorrectly assigned. What I am expecting is that despite how "confused" MS is in re to the initial import, once the file is in MSCZ format and I click on a single note and bring up the Properties, once I change the voice that is assigned to that note, then that note should now sound as I assigned it.

If this doesn't happen, what this means is that MS is retaining some kind of information from the initial import that it would not normally retain had the score been created from scratch in MS. I do not understand this. I'm expecting that if I do a "Save As" in MS, then it saves as a MSCZ file, rids itself of anything "XML" and is now in a state where the user can take over and fix the anomalies.

I am going to attempt this Dolet export but I guess I need to establish an account with MusicXML. I'll post the results here. Thanks.

OK, I'm just used to different semantics for submenus: Select -> All Similar Elements. The only mid-part instrument references that I could find in the score were Bass, so I followed your instructions and everything worked: the vocal parts are now voices and I did not have to re-select what is in the dropdown. The only staff that needs fixing is the drum kit, since it appears as though MS doesn't have anything the equivalent of "Drum Set". (As an aside, it sure would help if that massive instrument list were either sorted in raw alpha order, or grouped by instrument group w/headers and horizontal dividers.)

I'll go through the MS doco and learn how to create a drum set. (I've written tons of scores in MS but only head charts, so this is new territory for me...not a problem.)

The rest of the score has converted my ossia staves into standard, and assigned an instrument label to these. The staves that had multiple voices in them (not multiple instruments) that I used to indicate performance instructions for repeats have also been converted to just text. I'm going to experiment with playback (now that the playback button works) and see how MS "reads" these instructions.

Something that may be of interest to you is that once I got rid of the rogue Bass parts, the Not Responding issue went away. I have an 11th-gen i7 Windows machine with 32GB of RAM and a 1TB SSD, so there should normally be enough firepower for my purposes.

Thanks again!

Yes, and I fully expected to have to do some significant adjustments to the guitar sound once we went with live musicians. However, as I've mentioned, they need more to understand what they need to sound like than what exactly they need to play.

Because of the serious digital drops that I was getting from the Sibelius mixer production, I had to develop a number of scoring workarounds in order to get the overall parts to "emerge" in the mix. (This is a main reason why advice given to me was to forget Sibelius and use a DAW for my demos.) I would experience anomalies like a piano run playing a simple 10- or 12-note scale and along the way a section of the scale would simply vanish, as if the pianist had simply stopped playing. Adjusting the faders, dynamics in the score, etc., were either of little consequence, or they created fresh mix problems. I found myself playing Whack-a-Mole with the Mixer.

I found - interestingly - that adding notes to parts that I didn't necessarily want would "pop out" the ones I did want. For example, adding an addtional lower note to a guitar part took away the tinny sound, or making a scale run on the piano octaves instead of single notes actually brought out the "missing" upper notes. I know this is all engineering stuff, but I hadn't expected this to be such a battle. (I first engaged all this in the world of R2R one-inch tape 50 years ago, and we never faced blatant holes like this in our recording. A little working with the mix was all it took to at least get the sounds to "be there" even if the levels and balance were not what we wanted yet. One would expect that these issues would have been anticipated by the developers of digital music tools.)

The reason that the guitar parts in this score are sometimes ill-advised or even unrealistic is that when I attempted more-conventional voicings, the sound from the part was tinny and choppy. (Even in the final that you're seeing it's pretty bad, but still leaps and bounds ahead of when I started.) This goes from the strumming strokes, as well. I never could get the samples to respond to "up" or "down" strokes, and was told that the particular sample I was using did not include this data in it. (At the time I composed this score, I did not know that if instructions for articulation, dynamics, volume, etc., are not built into a sample, then it won't respond to these when inserted in the score. This drove me crazy because most of Sibleius' synth sounds would not even respond to volume changes, and the upright bass sounds had only one duration for plucking - no matter what I had composed in the score: staccato, 128th-note durations, etc.)

Thanks.