I don't have any experience with the 'machines' like Karaoke.

With software, the answer is, "it depends". Some musical sources work well enough, and some don't. I agree with John and Noel that a pitch change of 1/2 step is usually OK. Maybe you can push that to a full step. I had to take a song a minor third up once, and like you said, the 'color' of the sound changed substantially; it sounded 'hollow' and I did not want to use it, but the client insisted.

Use the best quality file you have to start with. Pitch shifting a .WAV file will be more likely to work without artifacts than the same shift on a .MP3 version of the same file. I listen particularly to cymbals; they seem to be the sound that degrades most and sounds odd when pitch shifted.

RealBand is not something I use, so I did not know there was a pitch shift capability. Impressive! For at least 15 years, I have used Adobe Audition (once Cool Edit) for all stereo .WAV file editing, and their pitch shifting algorithm is the best of the editors I've tried.

BIAB 2025 Win Audiophile. Software: Studio One 7 Pro, Swam horns, Acoustica-7, Notion 6, Song Master Pro, Win 11 Home. Hardware: Intel i9, 32 Gb; Roland Integra-7, Presonus 192 & Faderport 8, Royer 121, Adam Sub8 & Neumann 120 monitors.