With its 1.5 million words BLUR is the biggest electronic corpus of nonstandard English. The present study describes the stages in the design the compilation and the editing of BLUR and attempts to gauge its linguistic profit. This is done both from a theoretical perspective blues poetry vs. natural speech representativeness validity and from an analytical perspective in particular qualitative quantitative and comparative analyses of morphological morphosyntactic and syntactic features. The findings indicate that BLUR provides an outstandingly rich and reliable documentation of the vernaculars spoken by African Americans between the Civil War and World War II. The more than 1000 illustrative examples presented throughout this study attest to the correctness of this statement.