OK, last post on this for anyone else who might need it. It seems, at least on this machine, changes that occurred in version 3.14.0 are what led to the error in the original post. Version 3.13.1 went through with compilation. The other QB64 versions from 2.1 down to 1.5 worked as well.
The actual fix for QB64pe 4.2.0 on THIS machine was to copy "MIDIProcessor.o" and "MIDIProcessorRCP.o" from a WORKING installation of QB64pe 4.2.0 on another Linux machine (MX Linux 23.6). I stress working because it seems on a fresh install they are not present and are created the first time a compilation of code containing either of the PLAY or SOUND commands takes place. Also, copying the two files from version 4.2.0 on a different Windows 10 machine AND version 3.13.1 on this, the original Toshiba Chromebook 2, DID NOT work (to save someone the trouble).
The place the two files can be found in the QB64pe directory is:
(Your QB64pe Folder)/internal/c/parts/audio/extras/libmidi/
This all took place on a Toshiba Chromebook 2 (2014/ Baytrail) with Gallium OS 3.1, a specialized 64 bit Ubuntu 18.0.4 based distribution built specifically for Chromebooks. Sadly, it isn't updated anymore, but it sure is serving a purpose for me and this old unit.
Well I hope this helps someone else who might have run into this particular situation.
Thanks for the read and happy pluckin' everyone...
The actual fix for QB64pe 4.2.0 on THIS machine was to copy "MIDIProcessor.o" and "MIDIProcessorRCP.o" from a WORKING installation of QB64pe 4.2.0 on another Linux machine (MX Linux 23.6). I stress working because it seems on a fresh install they are not present and are created the first time a compilation of code containing either of the PLAY or SOUND commands takes place. Also, copying the two files from version 4.2.0 on a different Windows 10 machine AND version 3.13.1 on this, the original Toshiba Chromebook 2, DID NOT work (to save someone the trouble).
The place the two files can be found in the QB64pe directory is:
(Your QB64pe Folder)/internal/c/parts/audio/extras/libmidi/
This all took place on a Toshiba Chromebook 2 (2014/ Baytrail) with Gallium OS 3.1, a specialized 64 bit Ubuntu 18.0.4 based distribution built specifically for Chromebooks. Sadly, it isn't updated anymore, but it sure is serving a purpose for me and this old unit.
Well I hope this helps someone else who might have run into this particular situation.
Thanks for the read and happy pluckin' everyone...

