Tickets in both cities cost $12, students and the elderly pay $8.
Under current law, 42 percent of the elderly pay a surtax, which many consider an unfair burden.
The poorest 60 percent of the elderly pay no surtax.
Tickets for today's concert are $5, and students and the elderly pay $3 at the door.
An annual family membership costs $500, but the elderly pay about half that.
Admission is $5, students and elderly pay $4, children are admitted free.
Under the the new admission rates, the elderly pay $3, children pay $2 and an annual pass is $24.
House Republicans said they would set aside $40 billion over the next five years to help low-income elderly pay for prescription drugs.
And there are many ideas for making most of the elderly pay a larger share of their medical expenses.
Much of the contention is centered on programs to help the elderly pay for prescription drugs.
