The single most stunning Seattle Symphony performance I can recall was one of Mahler's Second Symphony, perhaps 12 years ago, when the musicians all outdid themselves: The orchestra played with impeccable polish and virtuosity, and conductor Gerard Schwarz brought the 80-minute work an overwhelming sense of sweep and drama. I specifically remember the awe I felt as I listened. Schwarz might agree that this work shows himself and the SSO at their best, since he's chosen it for this weekend's concerts—his farewell stand, after 26 seasons, as the SSO's music director. Neither his longest nor largest symphony, Mahler's Second may, however, be his most ambitious. In addition to its subtle, self-effacing subtitle, "Resurrection," the choral text is mostly written in the first person by Mahler himself. You have to admire the sheer cojones of a composer who (at 34!) could set lines like "With wings which I have won for myself/In love's fierce striving,/ I shall soar upwards/To the light which no eye has penetrated! . . . Die shall I in order to live" for an immense orchestra, two singers, an organ, and a chorus (not to mention two gongs, three church bells, and an offstage brass choir). So read what you like into Schwarz's choice of this symphony as his official last word. Opening the evening is the premiere of Philip Glass' Harmonium Mountain, last in the SSO's season-long series of Gund/Simonyi Farewell Commissions.