NEWPORT, R.I., July 4--Sen. Claiborne Pell (D.R.I.) will make the welcoming address here tonight before the opening concert of the tenth annual Newport Jazz Festival. The four-day festival, the largest jazz event in the country, is expected to draw more than 8000 fans to Freebody Park.

Local police have been augmented by 100 officers from other parts of the state to guard against a recurrence of the riot that marred the festival three years ago. Though festival visitors will not be allowed to camp out in city parks as in the past, they will be permitted to sleep on public beaches. Hotels and motels have been booked up solidly for several days.

The main events of the festival are four evening concerts to be held tonight through Sunday night. Except for Sunday's concert, scheduled for 6 p.m., all the concerts will begin at 8 p.m. The concerts will feature over thirty different jazz groups, including the Duke Ellington Orchestra, Thelonious Monk, Nina Simone, Dizzy Gillespie, Gerry Mulligan, Sunny Rollins, Dave Brubeck, John Coltrane and Maynard Ferguson.

A new festival event, to be held tomorrow at 2 p.m., will be a "New Faces in Jazz" concert. This event will feature the Paul Winter Sextet, which recently became the first modern jazz ensemble to play at the White House. Prof. Marshall Stearns of the City College of New York will produce a program of tap dancing on Saturday afternoon.