Elly Ameling will sing a Lieder recital tonight at 8:15 in Tawes Theater at the University of Maryland. The noted Dutch soprano will give a master class at the university tomorrow at 1 p.m. Her pianist, Dalton Baldwin, also will give a master class during the week. For details on the concert and classes, call 454-3347.

Julius Rudel will continue his series of Mahler symphonies at Wolf Trap on Thursday night, July 7, when he conducts the Fourth Symphony with soprano Janice Hall as soloist. The program also will include the New World Symphony by Dvorak.

The National Symphony, in addition to a number of concerts at Wolf Trap this summer, will open its annual summer concerts in the Kennedy Center on July 15 at 8:30 when Max Rudolf will conduct a Beethoven program will conduct a Beethoven program with Rudolf Firkunsny as soloist. With the same conduct and soloist, a Beethoven cycle that will include all the piano concertos will be played on July 15 and 17, 22 and 24. Later concerts will bring the Violin Concerto and the version of that work which Beethoven made for piano soloist, as well as the Ninth Symphony.

Guest conductors appearing with the orchestra during July and August are Rudolf. Everett Lee. Eduardo Mata, Rafael Fruhbeck de Burgos, and Hioyuki lwaki. Soloists will include Firkusny, Ruggiero Ricci, Hans Richter-Haaser, Walter Klien, Aaron Rosand, Garrick Ohlsson, Boris Belkin, Gary Graffman, Aldo Ciccolini, and singers Donald Gramm, Ruth Welting, Alan Titus, George Shirley, Joyce Simpson, Nancy Tatum, Mignon Dunn, and Dean Rhodes.

The Oratorio Society of Washington will join the orchestra in Orff's "Carmina Burana" and the Beethoven symphony in which the soloists will be Deborah Lucas, Marianna Brusching, Curtis Rayam, and Mark Munkittrick.

The concerts will be played on successive Friday, Saturday and Sunday nights, with a different program each night. Ticket prices range from $2 to $7.50.

Festivals: The Newport, R.L. Music Festival opens on July 20, offering 31 concerts in 11 days. Among its programs will be three saluting the challenging entrant countries - Australia, France, and Sweden - in this year's America's Cup Race. The festival will feature a dazzling array of pianists, singers, chamber music and ballet. For details, write Newport Music Festival, 50 Washington Square, Newport, RI, 02840.

From Charleton, S.C. comes word - from Mayor Joseph T. Riley and director Gian Carlo Menotti - that the recent Spoleto Festival in Charleston was so successful that next year's will be expanded from12 to 15 days.