The easiest way to answer this would be to say, Just buy the most expensive. However that is not necessarily the best way. The important thing is that the player should be happy with the instrument. Playing the violin is a uniquely personal thing and many violinists will tell you that they get very attached to their instrument.
For a beginner, choosing a violin is even harder because they probably don't have any playing experience to help them make a decision. The most often quoted advice is to take your teacher along and get them to play the instrument you're interested in. However that might not be a practical suggestion, our experience is that the average Violin teacher is too busy trying to fit all their pupils into their busy schedule to be able to spend time visiting music shops with pupils.
The other common advice is to visit your local music shop where you will find a bunch of caring people to help with your decision. Maybe those places do exist but our experience has been that either the staff don't really understand violins or the environment is far from comfortable and the whole choosing business is quite stressful and intimidating.
Our solution to the choosing problem is to offer a wide choice of violins that are correctly set up and to allow you to buy and try. We are happy for you to buy a violin from us and keep it for up to a fortnight. During that time you can play it at home where you feel comfortable and at your lesson with your teacher. If you decide the instrument is not for you or you'd like to try another you can return the violin and we will refund your money including our delivery charge. Some people buy two or three violins, try them out, keep one and return the others. As long as the violins are returned in good condition we give a full refund.
This to a certain extent depends on the cost of the violin. It is probably unreasonable to expect a cheap student outfit with steel strings to sound like a more expensive hand made violin with strings that cost as much as the cheap student instrument.
First things first, is the violin comfortable to play. Are the string heights correct?, you shouldn't need to press too hard to stop the strings. Is the bridge set up correctly? can you bow each string without catching one of the other strings?. Now analyse the sound, does it sound nice to you?. It often surprises me when I give a customer several violins to try, how often they buy one that I thought had an inferior sound to some of the others. It matched their idea of a good sound, they were happy and in most cases they stay happy.
Other things to look for are the quality of the bow, does it feel balanced in your hand?, does it draw a note from the string easily and throughout it's length? Is there plenty of hair on it and when you look along it with the hair pointed towards the floor is it straight?. Lastly does the adjuster turn fairly easily and can you get the bow as tight as you want and loose enough for the hair to just touch the stick?
Examine the violin for cracks, especially if it is an older instrument. Check that the neck hasn't moved, you'll see a gap between the button on the back of the violin and the heel of the neck where it joins the body of the violin. The odd mark and chip on the varnish is not really going to affect the sound. Substantial areas of varnish missing or badly worn can be a problem as dirt and oil from your hands can get into the wood.
If possible get someone else to play the violin while you listen, you might be surprised how some element of the sound, which might worry you and is obvious to you with the violin a couple of inches from your ear is not at all apparent when you are a few feet away. It's a curious fact too that even the most ordinary violin can sound wonderful in the hands of a good violinist.
We hope that helps you to find your dream instrument. Don't forget our Buy and Try service