Experienced buyers of live music and institutions that use entertainment regularly already know what to look for in a performer.

But members of the general public who need live music maybe once in a lifetime, say for a wedding or a party, often don't know how to choose from among the many offerings.
Of course, every act says they're great. But how can you tell beforehand that they really are?
And what does "professional" mean?

Members of other professions (physicians, lawyers, accountants, etc.) have managed to ensure by legislation that only qualified people are allowed to work alongside them. That kind of selective process is absent in the music business. Anyone who can bang out a tune on an instrument can call him/herself a "musician" and solicit work from an unsuspecting public.

Keep one fact in mind: the music business is like any other business and normal standards and business practices apply. The quality of the product or service is usually reflected in the price.

Here's what to look for:

Longevity:

How long has the business been operating?
Do they have a track record? How successful are they?

Do they actually perform music for a living, or is it merely a hobby?

What's their H.S.T. (G.S.T.) number?

If they don't have one, that means they are amateur performers and their revenue is below the legal threshold. Not exactly confidence inspiring; what does that say about the quality of their presentation?

Are they members of a professional guild or association?

Full time players usually belong to the AFM (American Federation of Musicians of the United States and Canada).

Where do they perform?
What kind of audiences do they attract?
Are they the kind of people with whom you would normally socialize?

Will they show up properly attired, or get up on stage in their street clothes?

Will they show up well before starting time?

Will they show up sober?

Will they show up at all?

Professionals have dedicated their lives to excelling in their chosen field. By education, background and experience they stand miles above amateurs (the word comes from the Latin "amo" - to love) who come from various walks of life and have acquired some musical skills - mostly for their own enjoyment.

To put it another way:

Would you board a plane that's piloted by a baker who has taken a few flying lessons in his youth?