Simplify the following text for a Grade 5 native English-speaking person.
Original: He performed songs such as `` Got My Mojo Working '' and `` She 's Nineteen Years Old '' , although he did not appear on the original recordings ; long-time Muddy Waters harmonica player Little Walter was utilized on most of Muddy 's recording sessions in the 1950s .
Simplified: He performed songs like `` I Got My Mojo Working '' and `` She 's Nineteen Years Old '' .