The current American tour by the Israel Philharmonic Orchestra, a seven-city, eight-concert trek that reached Carnegie Hall on Tuesday night, was meant to be a festive occasion. Doubly so, in fact. The orchestra, founded as the Palestine Symphony Orchestra in 1936, is celebrating both its 75th birthday and the 50th anniversary of Zubin Mehta’s first conducting engagement with it in 1961. Mr. Mehta, 25 when he first led the orchestra, became its music director in 1969. In 1981 his appointment was extended for life.

Unquestionably Mr. Mehta and the Israel Philharmonic make up a significant and valuable artistic alliance. Still, not everyone was of a mind to celebrate. Opponents of the Israeli government’s policies and actions toward the Palestinians have deemed the orchestra, in its role as one of Israel’s most visible and successful cultural exports, complicit, however quietly. On the Internet activist organizations called for demonstrations and boycotts during the tour.

On Tuesday a small band of vociferous protesters wielded signs and chanted slogans through bullhorns across 57th Street from Carnegie Hall’s front doors. Handbills likening Israel’s policies to South African apartheid littered the sidewalks. One news agency reported that security measures had been increased in anticipation of such protests.