Mark Tremonti was sitting atop the hard-rock world in the early 2010s. Having cofounded two successful acts in Creed and Alter Bridge, he was a highly revered guitarist, songwriter and collaborator. But with a backlog of tunes piling up, he decided to add yet another project to his schedule. While his eponymous project retains the melodic hooks of the musician’s other groups, Tremonti’s deployment of thrash riffs and speedy tempos provides a hard-edged attack steeped in heavy metal. This is especially true of A Dying Machine, a 2018 science-fiction-informed concept album that boasts the epic feel of old-school Metallica.