At midnight tonight EZ Communications is officially changing the call letters of WEZR-FM (106.7) in Fairfax to WBMW, introducing a new logo and slightly modifying its pop music format.

To go along with the new call letters, WBMW will have an advertising and community service campaign built around a bee mascot dressed in yellow sneakers. The new slogan is "B-106.7," replacing the line "Washington's EZ Rock." Since Dec. 26, the station has been "teasing" listeners by announcing that "WEZR is the new WBMW" and that "There's a buzz in the air." The station's adult contemporary format, its programming thrust since June 1983 when it switched from nearly 15 years as a beautiful music station, will now include more up-tempo pop songs.

"WEZR had an identity problem with the call letters. Coming after all that time as a beautiful music station, an easy rock station wasn't establishing itself," said general manager Bonnie Brooks Reich. "The 'B' call letter and the bee symbol will give us a strong identity and we plan to do more community involvement."

WEZR, the 19th ranked station in the market, trails far behind the other adult contemporary stations in the listener surveys, due to a past problem with a poor signal and the hard-to-erase image of a background music station geared to the older demographic. WEZR started operating from a new tower last July that was 12 miles closer to the center of Washington. According to Jeff Ballentine, the program director, "the new tower almost doubled our coverage. It made us a competing radio station."

WEZR's highest rating ever was a 3.2 share in fall 1981. Since the station changed its format to adult contemporary, it earned a 1.2 share in summer 1983, 1.4 in fall 1983, 1.2 in winter 1983, 1.5 in spring 1984 and 1.8 in summer 1984. With the new thrust, Ballentine said, it is trying to compete directly with WRQX-FM, the number five station in the market with a 5.6 share, and WPGC-FM, number seven with a 4.6 share.

While the station's ratings were disappointing, said Dick Eury, the general sales manager, its revenues increased by 50 percent in the last 18 months and it had a respectable 194,500 listeners who tuned in at some point in the week in the total survey area. "Our real target is the 25-34 demographic. 27.1 percent of the 18-plus population is 25-34. Out of our summer book total listeners, 67 percent are 18-34," said Eury.

The "B" logo has been used by the EZ company in two other markets, Pittsburgh and New Orleans. Reich came to WEZR in September from WEZB in New Orleans. Ballentine joined the Fairfax station in August from WBZZ in Pittsburgh. Reich said when the New Orleans station changed from beautiful music to Top 40, it became the number one station in the market in its first ratings book.

The hybrid format at WBMW, said Ballentine, will continue to feature four in a row and three commercial breaks an hour after the conclusion of the John Murphy morning show and will "be heavy on adult contemporary and light on Top 40."

The station executives said no changes are planned with the on-air staff.