Thanks for reporting. Looks like this package was removed between 14.04 and 16.04, please see https://launchpad.net/ubuntu/+source/mp3gain/+publishinghistory and https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=761847 for more details. The latter mentions python-rgain as an alternative.
** Bug watch added: Debian Bug tracker #761847 https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=761847 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1758484 Title: missing package in 17.10 To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/mp3gain/+bug/1758484/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
