Hi ursa292,
Thanks for contacting us here in Apple Support Communities. We understand that your MacBook Air is starting up to a blank screen and playing the start up tone repeatedly. The good news is that you're in the right place for help.
Since resetting the NVRAM didn't resolve the problem, the next step we would suggest is trying to start the MacBook Air in recovery mode, and then see if you're able to run Disk Utility. This will allow you to run First Aid on the hard drive. We have more details about that process in the resource below.
If your Mac starts up to a blank screen
If your MacBook Air doesn't start up in recovery mode, we'll want to explore service options to have your Mac inspected by a technician.
Please let us know if you have any other questions or concerns. We're here for you, and would be happy to assist again.