For more than 10 years, Donal Fagen and Walter Becker have been (with the help of an assortment of musicians) the rock-jazz fusion group "Steely Dan." But now Fagen and Becker are each pursuing separate projects. Fagen says, "We have worked together for over 10 years and at this time need a change of input," but he shies away from saying that the group is "breaking up." Fagen is due to start recording his first solo album in August. Becker, on the other hand, is in a typical music business state --- negotiating future projects . . .

Sixth Street between First and Second avenues in New Ork City is the site of at least a dozen good, cheap Indian curry houses. It is also the site of an unusual piece of sculpture. Artists Jill Fleishmnan and Liz Cash have strung a bra 20 feet from strap to strap and a pair of panties size 13 (feet that is) across the street. The foundation sculpture is made of muslin, wire, paint and ribbon . . .

Last Sunday, Jane LaPotaire won a "Tony" for her performance as "Piaf." But the box office, which has been weak for a long time, did not improve and so the show is scheduled to close after today's matineee. A source with the show said that the best houses came when Elizabeth Taylor was unable to perform across the street in "The Little Foxes," and "Piaf" picked up a little of that business . . .

"The World According to Garp" is being filmed at various places along the East Coast this summer and fall. The script was written by Steve Tesich, who wrote "Breaking Away," and among the film's stars are Hume Cronyn and Jessica Tandy, who starred in "The Gin Game," and Mary Beth Hurt . . .