What is the name of the pentalogy which features Dedication 3 and Dedication 4?
Dedication 4 Dedication 4 is a mixtape by Lil Wayne. The mixtape was originally supposed to be released on August 15, 2012, but got pushed several times  and was released on September 3, 2012. It is the fourth installment of Lil Wayne's "Dedication" series, following its predecessors "The Dedication", "Dedication 2" and "Dedication 3". It's also the fourth installment of Lil Wayne's "Gangsta Grillz" pentalogy.
Sub Arturo plebs "Sub Arturo plebs" is a composition in three voices ("tenor", "motetus" and "triplum"). Like all medieval motets, it has separate texts for each voice, which are sung simultaneously. All three texts are in Latin; the title under which the work is conventionally known in scholarship today consists of the opening words of each text. Their subject matter deals with music and musicians, following a tradition of similar "musician-motets" known from contemporary France. It includes a named reference to the composer of the work, making him one of the earliest named English composers, and a self-referential description of the work's own structure.