One of the greatest musical talents in all of music has decided to end his current (and final) tour because of Alzheimers Disease.

(AP) - Glen Campbell's touring days are over. But that doesn't mean it's the end of the road for the country legend.

He spent his 77th birthday yesterday in Washington D.C. as an advocate for research into Alzheimer's disease - the illness that has progressed so far, it has stopped him from doing concerts. Among his scheduled stops yesterday: Capitol Hill for a visit with lawmakers.

His wife Kim says Campbell still occasionally does vocal tracks, remains healthy - and can still jam on the guitar with other musicians.