Is it possible to get promoted this quickly in the Air Force? Is this typical for band members?

Normal for trained musicians. Navy is the same way, all they do is play music, usually at command functions. Similar to the medical/dental program for officers except they are enlisted of course. IIRC, the Navy ones go through boot as E3s and put on their actual rank at/after graduation.

Thanks for raising your right hand and deciding to serve in your own way.

E-6 is automatic for the premier service bands in Washington DC. There are often over 100 applicants for one spot. These folks are the best of the best and are trained and qualified before enlisting, unlike most other service members. Mostband members have at least a bachelor's degree and many come with master's and doctoral degrees. It is unusual for a 19 year old to be accepted, but I tip my hat to her for this accomplishment.

Mike McDonald,
Master Chief Musician (ret)
U.S. Navy Band

The answers to these questions are located in the specific regulations or instructions.
AFI36-2502 Chapter 5
PREMIER BAND ENLISTED PROMOTION AND PROPRIETY REVIEW PROCESS
5.2. Background. To support CONUS and worldwide mission requirements, Premier Bands access fully qualified professional musicians. Premier Band members are by-pass specialists who do not enter into formal upgrade training to attain craftsman (7-skill level) designation. Air Force Premier Bands compete with the other services' premier bands and the civilian sector in recruiting fully qualified professional musicians. While assigned to an Air Force Premier Band, members are deferred from rotational PCS moves. Special enlisted promotion authority is granted only for band members assigned to Premier Bands because:
5.2.1. Recruiting fully qualified professional musicians saves training costs and time.
5.2.2. Recruiting and retaining fully qualified professional musicians to Premier Bands requires an incentive.
5.2.3. Members are deferred from rotational PCS moves and must compete for promotion to internal vacancies rather than external quotas.
5.4.1. Due to the highly specialized nature of positions in the Premier Bands, The USAF Band and The USAFA Band conduct separate promotion processes based on internal unit vacancies. Promotion to TSgt is effective upon the day the member first reports for duty with a Premier Band and requires the approval of the promotion authority or their designated representative. There are no TIS or TIG requirements.

It's important to note this is the Air Force band. If she were to go to the real airforce (all jokes aside), she would lose that rank. This is simply market pay compensation for skill.

Even the Marine Corps has a professional musician hiring process that had promotion authority independent of the system. Its unique to that program. This appears to be that type of situation.

No this is not typical. I don't care what the AFSC is. I would have a hard time taking orders. I would but she has done nothing to earn the respect and authority that rank holds. Complete disrespect to all who legitimately earned it.

I'm pretty offended by the people bitching about rapid promotions. I went in the Navy as a nuke. Pretty much everyone I knew was E5 out of nuke school...and though I ended up getting a medical discharge...I'm sure plenty of them made their E6 by the end of prototype...which if their timing worked out right would easily have made it just as fast or faster. We all worked our asses off getting through school. Every one of them deserved at least that. Most of them left after their initial 6 because it was more profitable to take that hard work and double or triple their pay in the private sector. Anyone that has a problem with people that can qualify for a fast progression because of skills, education, need of the service or whatever can all pretty much go fuck themselves.

It is not for anyone to judge or try to justify why this happens. All branches and service jobs have predetermined criteria. For example Dr's , upon graduation are immediately 0-3 entering service, or Army Warrant Pilots, which could be as young as 18 , after about 6 weeks of WOCS, are officially WO1's. I knew the second youngest WO1 pilot , he was 19. What doesn't make sense to the majority , makes perfect sense to the minority. As I have seen posted already if we took the time to read the regs then it would be clear to all why this 19 year old made E-6 in the AF Band.

Coast Guard is the same way....join the band, automatic E6