Simplify the following text for a Grade 13 native English-speaking person.
Original: They are signed with Warp Records and have released several works on that label with little advertising and few interviews , while also having an elusive and obscure back-catalogue of releases on their self-run Music70 label .
Simplified: They are signed with Warp Records and have released several works on that label with little advertising and few interviews , while also having a secret , privately-released back-catalogue of albums on their self-run Music70 label .