Possible Clues:

• Symphonic gp
• Theater ticket abbr
• Philharmonic grp.
• Seating sect.
• Gp. with brass
• Conductor's group: abbr
• N.Y. Phil, for one
• Sect. on a concert ticket
• The L.A. Philharmonic, e.g
• N.Y. Philharmonic, for one