Base distro and package repros
We need a strong foundation with access to the latest software.
Understandably, all of these distributions only offer 64-bit builds. They all have some capability as a live distro. For some of them, the preferred base distro will come down to personal preference and previous Linux experience.
AV Linux is based on MX Linux, which itself is based on the stable branch of Debian. This gives command-line tools that will be largely familiar to users of other Debian derivatives, such as Ubuntu and Mint. It draws its packages from the MX Linux repositories, which is a mixed blessing. In some areas, these repositories are ahead of what Ubuntu Studio has to offer in the way of audio software; in other areas, Ubuntu Studio has the more up-to-date packages.
Fedora Jam and Fedora Design Suite are spins of Fedora Linux, and therefore use the Fedora repositories and Fedora commandline tools, such as the DNF command-line package manager. These repositories are, overall, slightly ahead when it comes to offering up-to-date music tools. In addition, both distros have access to Flatpak packages by default.
Making the issue more complicated, the Debian/Ubuntu-based distributions can add the KXStudio repositories, which are the most up to date repositories of multimedia tools and applications, a big advantage. PPAs are another source of up-to-date software.
Modicia OS is based on Ubuntu LTS, which might be a disadvantage as some cutting-edge media tools, particularly plugins, require bleeding-edge libraries. Ubuntu Studio, on the other hand, offers LTS and current stable release versions.