In his far-flung jazz career, pianist Dillwyn "Dill" Jones, who was born in Newcastle, Wales, pursued his musical interest in Ceylon (with the British Navy during World War II) and London (where he hosted his own radio show).

He first visited this country in 1950 as shipboard pianist of the Queen Mary and settled in New York in the early '60s.

"I was coached by the late pianist Luckey Roberts," Jones recalled recently. "Luckey told me that James P. Johnson, Fats Waller and all the stride pianists in New York, Washington and Baltimore adored the music of Franz Liszt and other classical composers and they always had them up their sleeves just in case, to show that they knew what they were about."

Jones himself, in addition to knowing what the classics are about, is an accomplished stride pianist as well as a major interpreter of Bix Beiderbecke impressionism, a band pianist who can drive a traditional unit with the best of them, and a mainstream modernist who can cut the works of Bud Powell.

Jones underwent surgery to arrest cancer of the larnyx in February and reentered the hospital last week for additional surgery. A benefit for the ailing pianist will take place this afternoon from 1:30 to 6:30 at the Old Town Ramada Inn, Alexandria. Among the 40 or so performing musicians will be trumpeter Billy Butterfield, drummer Cliff Leeman, vocalist Barbara Lea and reed player Mason "Country" Thomas. The Manassas Jazz Festival and the Potomac River Jazz Club are the sponsoring organizations.