By PETER COOPER – The TENNESSEAN, Saturday May 14/2005

Jimmy Martin, the brash fireball whose electrifying stage presence and soaring vocals made him one of bluegrass music's most consequential and colorful artists, died this morning at a Nashville hospice from complications of bladder cancer. He was 77. Known as ''The King of Bluegrass'' and ''Mr. Good'n Country,'' Mr. Martin became known as a master of American roots music. In 1949, Mr. Martin successfully auditioned for Bill Monroe's Blue Grass Boys and his vocal contributions ushered in what is now known in bluegrass as the ''high, lonesome sound.'' ''Jimmy's strong, high vocal range pushed Monroe's tenor up into the sky, helping shape what has become known as the ''high lonesome sound,'' wrote George Goehl in the liner notes to Don't Cry To Me, a compilation that accompanied Goehl's King of Bluegrass documentary.

Mr. Martin's contributions went beyond the bluegrass field. His was the first voice heard on the first Nitty Gritty Dirt Band's Will The Circle Be Unbroken album, and he sang on the subsequent two volumes as well, appearances that brought his voice and feisty spirit to audiences that would never have thought to attend a bluegrass festival.

''Jimmy's temperature is higher than the rest of ours,'' said Dirt Band member Jeff Hanna, in a 2002 interview. ''He's a wild man in the best sense of the term, and he's the only one who brought the fire of rockabilly music to bluegrass.'' On those three Circle albums, Mr. Martin provided a bridge between old-time bluegrass and new-world country music, something that came to him fairly naturally. He'd always been one of bluegrass music's most commercially viable exports, and recordings such as (I've Got My) Future On Ice and Widow Maker could frequently be found on country jukeboxes and on country radio playlists.

Mr. Martin's mercurial personality also interested audiences outside of bluegrass, and he was the subject of a book called True Adventures With The King of Bluegrass and a DVD called King of Bluegrass: The Life and Times of Jimmy Martin. With Monroe, Mr. Martin recorded songs including My Little Georgia Rose, Uncle Pen, In The Pines, Memories Of Mother and Dad and The Little Girl and the Dreadful Snake. His rock-solid rhythm guitar was heard to great effect on the instrumental, Raw Hide. He later claimed to have assisted Monroe in the writing of Uncle Pen, Memories of Mother and Dad and others.

Mr. Martin left Monroe in 1951 and returned for another stint beginning in 1952. Two years later he began his solo career in ernest, recording first for RCA Victor then Decca. Among his recordings were the now-classics Ocean of Diamonds, Saphronie, Hold Whatcha Got, My Walking Shoes, Hit Parade of Love, Sunny Side of the Mountain, Widow Maker, (I've Got My) Future On Ice and Milwaukee, Here I Come. His outlandish, energetic performing style made him a star on radio shows including the Louisiana Hayride and the WWVA Jamboree in Wheeling, W. Va. ''In his heyday, he could take an audience of any size and have them eating out of his hand,'' said Sunny Mountain Boy Emerson. ''He'd just smoke those people, and they'd be waiting in line for him when he got offstage.''

In 1995, Mr. Martin was inducted into the International Bluegrass Music Association's Hall of Honor, and he borrowed the text of the Hall of Honor plaque for use on his own gravestone. The stone has been on display for more than five years at Spring Hill Cemetery in Madison. Mr. Martin was thrilled to find a plot directly across from Country Music Hall of Famer Roy Acuff, and delighted in the notion that the ''King of Country'' and the ''King of Bluegrass'' would rest in eternal proximity. Despite the acclaim, he never became a member of the Grand Ole Opry — a fact that pained Mr. Martin. Mr. Martin sometimes cried when he spoke of being left off the Opry roster, which he equated with the loneliness he felt after his father died.

''Ever since I was a little boy, I've felt left out of things,'' he told the Tennessean several years ago. Mr. Martin was born in Sneedville, a farming community in the state's eastern hills. His father died when he was 4, and Mr. Martin spent much of his childhood plowing corn.

He died just before 9 a.m. today at Alive Hospice, said his longtime manager Lance LeRoy.

Survivors include three sons, Timmy Martin of Fort Lauderdale, Fla., Ray Martin of Mt. Juliet and Buddy Lee Martin of Miami; a daughter Lisa Arnold of Hendersonville; and three grandchildren.