Buying a used instrument

The used market is where the value is, and it is also where the expensive mistakes are. The difference between the two is almost entirely the source, not the price. A used clarinet from a music shop that has repadded and adjusted it is a genuinely better instrument than a new one at the same money. The same clarinet from a garage sale, last played in 2009, is a bill.

Rank your sources before you rank your options

What to check, by family

Brass — trumpet, trombone, baritone

1. 1

   Work every valve or the slide

   Valves should drop under their own weight when the horn is tilted, and return smoothly. A sticking valve may only need cleaning and oil, or it may be a bent piston, and you cannot tell from outside. On a trombone, the slide should move its full length with one finger.

2. 2

   Pull every tuning slide

   Every slide should move. A slide seized by corrosion is a workshop job, not a home fix, and on a cheap horn the repair can exceed the instrument's value.

3. 3

   Look down the leadpipe

   Shine a light in. Red or green corrosion, or visible build-up, means a chemical clean at minimum. It is not fatal, but it is a cost.

4. 4

   Check dents against where they are

   A dent in the bell flare is cosmetic. A dent in the leadpipe or a tuning slide affects how the instrument plays and is expensive to fix properly.

Woodwind — clarinet, saxophone, flute

1. 1

   Inspect the pads

   Look at the leather or synthetic discs under each key. Torn, hardened, or discoloured pads mean a repad, and a full repad on a student instrument frequently costs more than the instrument is worth. This is the single most important check.

2. 2

   Test the seal

   Close the keys and cover the ends of the joint, then apply gentle suction. It should hold. Air escaping means pads that are not seating, which is the same repad problem.

3. 3

   Check for cracks on a wooden body

   Grenadilla clarinets and oboes crack, usually along the grain near the tone holes. A crack is repairable and it is never cheap. On a plastic or resin body this risk does not exist at all.

4. 4

   Ignore the mouthpiece entirely

   You are replacing it regardless, and a used mouthpiece from an unknown player is not something to put in a child's mouth. Price the instrument as if it has none.

Strings — violin, viola, cello

1. 1

   Look along every seam and the top

   Open seams are normal and cheap to reglue. A crack through the top, especially near the soundpost, is a serious repair and can exceed the value of a student instrument.

2. 2

   Check the soundpost is standing

   Look through the f-hole. There should be a small wooden dowel standing upright inside, near the bridge. If it has fallen, do not tune the instrument up — take it to a shop.

3. 3

   Test whether the pegs turn and hold

   Pegs that slip or seize are common on instruments that have been stored badly. It is a modest repair, but a violin that will not hold pitch is unusable until it is fixed.

4. 4

   Sight down the bow

   A warped bow with a sideways twist is not worth repairing on a student outfit. Bows are the cheapest part to replace and the most commonly ruined by storage.

Guitar

1. 1

   Sight down the neck from the headstock

   A slight forward bow is normal and adjustable. A twist along the neck's length is not adjustable and makes the guitar unplayable in some positions. Walk away from a twisted neck.

2. 2

   Check the string height at the 12th fret

   High action is usually a setup issue and cheap to fix. Very high action combined with an already-flat bridge saddle can mean a neck reset, which on a budget guitar is not economic.

3. 3

   Look where the neck meets the body

   Any gap or lifting at that joint is a serious structural problem. This is the guitar equivalent of a soundpost crack.

The question that tells you the most

Ask the seller when it was last serviced and by whom. A seller who names a shop and a rough date is telling you the instrument has been looked after and probably plays. A seller who does not know is telling you to budget for a service, which is fine as long as you actually budget for it. A seller who says it does not need one is telling you they have not looked.

Second best question: ask them to play it, or to send a short video of it being played. An instrument nobody can make a sound on is an instrument with a problem, and it is remarkable how often that request ends a conversation.