"The Lost Tapes" features introspective lyrics and themes of urban life, sociology, and despair. Its music is characterized by low-key beats, sparse production, subtle string flourishes, mellow piano work, and subdued soul music loops. "Stylus Magazine"s Brett Berliner said songs such as "Doo Rags" and "No Idea's Original" incorporate classical melodies, while songs such as "Purple" and "Fetus" feature neo-classical themes. John Bush of AllMusic said the songs "have more in common with his early recordings; there's more of a , wasn't-it-all-so-simple-then sound to 'Doo Rags' and 'Poppa Was a Playa,' two tracks that definitely wouldn't have fit on the raging "Stillmatic"." Music writer Craig Seymour observed "spare beats" in the music and few boasts in Nas' rapping, while Chris Conti from the "Boston Phoenix" said the simple beats "counteract Nas's complex bars of braggadocio and street-life storytelling."