The rapper fails to show up at the annual 'Monster Fest'...

Rapper DMX failed to show for a concert in BOSTON last night (October 29).

The star had been a late addition to the line-up of the annual ‘Monster Fest’, stepping in for Ja Rule, who pulled out because of a scheduling conflict involving a movie shoot. Monster Fest, the annual hiphop extravaganza put on by Boston’s Jam’n 94.5 FM, featured sets by P. Diddy and the Bad Boy Family, Missy Elliott, Eve, City High,

Fabolous andNate Dogg

, as well as an acoustic set by Craig David.

No explanation has been offered as to whyDMX, the leader of Ruff Ryders collective, did not appear.

As revealed previously on NME.COM this current US tour has not been plain sailing for DMX. Authorities in New York have blocked plans for a free outdoor show in the city – as part of promotion for new album ‘The Great Depression’ – because they were worried about guaranteeing the safety of a large crowd in the wake of the September 11 terrorist attacks.