I have started using Tux Guitar. It’s an open source version of Guitar Pro, and can read Guitar Pro files.
Love the 2014 version of rocksmith. You can find a Crack and set it up with minor technical knowledge.
I bought the full version of Transcribe!. Has a lot of features and runs under Linux.
LSD
Not exactly what you are looking for I don’t believe, but I use a Fender Mustang Micro for a portable practice setup for guitar/keys and use the bluetooth connection to play whatever song I want through the Micro.
I mean … YouTube? You can change speed and jump around. No loop though.
MIDI files in a DAW would be better! Can change loop and tempo. Use something free and download the MIDI from online
Yep, and you can grab an extension like Enhancer for YouTube to get customized looping behavior too.
I just use Spotify at normal speed
Audacity.
Capo on the Mac.
Up Tempo on my phone. Android and iOS versions available.
Free version has been handling my speed and pitch changes fine and can loop sections, the whole song, or play/shuffle a whole playlist.