The opening and ending themes and the insert songs are performed by individual members or a subset of members of Project.R. Several songs are performed by long standing theme song singers who are not included as being members of Project.R (the songs are composed by Project.R members, though).
Lagu pembuka dan penutup serta lagu sisipan semua dilakukan oleh anggota individu atau bagian di anggota Project.R. Beberapa lagu dilakukan oleh penyanyi lagu tema berdiri lama yang tidak termasuk sebagai anggota Project.R. (lagu-lagu digubah oleh anggota Project.R, meskipun).