 The sampled content on Endtroducing ..... originates from various sources , including music of genres ranging from hip hop , jazz , funk , psychedelia , and heavy metal as well as films and interviews . DJ Shadow layered , programmed , and cut samples into smaller fragments to create new tracks . He opted to sample from more obscure selections , making it a personal rule of his to lean away from using more popular material , saying : " I 've always pushed myself to use obscure things , and if I use something obvious , it 's usually only to break my own rules . " Samples of more prominent artists such as Björk and Metallica are , however , present throughout the record . Minor vocal contributions were provided by American rappers Lyrics Born and Gift of Gab , both personal friends of DJ Shadow . 
