We are trying to purchase advance tickets for March 31 flamenco show at Palau de la Musica and can't get it to go through. Any tips/tricks appreciated. Thanks.
Try a different device, i.e. computer vs phone vs different phone.
Also worth trying:
A different browser on your PC
Every credit card you own
A debit card
Cellular-data connection rather than home Wi-Fi
Edited to add: Sometimes calling the credit card company to report a planned overseas purchase works.
From recent experience, they don't take American Express. I tried a different credit card and it worked.
Take a look at this thread from yesterday for a possible explanation and some options you might want to try: