The final concert of the fall PIPES series highlights the significant role Trinity’s new organ will serve for the church’s choirs and congregation for years to come. The talented musicians of Trinity Youth Chorus sing their own adaptations of two masses: Gabriel Fauré’s Messe basse, originally scored for upper voices, and Maurice Duruflé’s Messe Cum Jubilo, the composer’s last large-scale work written for baritones and a baritone soloist. Rounding out the program is a favorite: Fauré’s beautiful Cantique de Jean Racine.