A great instrument, by which is meant a serious example of a serious maker, is catalogued more thoroughly than almost any other possession. The Hill brothers' Stradivari catalogue, its modern successors, and the equivalent works for the makers of other periods are, in their way, among the most precisely maintained registers of private property in existence.

The catalogue records the instrument's measurements, its varnish, its peculiarities, its repairs, and, crucially, its sequence of owners. Each named owner is recorded with the dates of their custody where these are known. A famous instrument, by an important maker, has typically been catalogued in successive editions across more than a century. Each edition refines the entries of the previous one.

The catalogue is not, in its modern form, narrowly held. The scholarly editions are in the libraries of every conservatory and major auction house; the digital extensions of those catalogues are accessible to anyone with reason to consult them. A determined enquirer can establish, with reasonable accuracy, who currently holds which great instrument; for many of the most famous pieces, the holder is, in effect, public knowledge.

The auction record adds further detail. The major sales houses publish their catalogues with provenance entries, named former owners where consent is given, and exhibition histories. The buyer is sometimes named immediately; more often the name appears in subsequent commentary, in scholarly notes, or in the next sale.

Insurance generates a parallel record. A serious instrument is insured for its value; the schedule names the owner, the address, and the conditions of storage; the record is renewed annually and accumulates in the insurer's files. The insurer's appraisers are, in many cases, the same people who maintain the catalogues; the records, although private, sit close to the published ones.

Performance creates further visibility. A player who uses a great instrument, whether their own or one borrowed from a foundation or private owner, typically acknowledges it in concert programmes. The acknowledgement is in the printed programme, on the broadcast credits, and in the press coverage of any significant performance. The instrument and its owner become matters of professional and journalistic record.

Charitable lending arrangements add their own layer. Many of the most famous instruments are owned by foundations and lent to performers; the lending is publicised; the foundation's filings name the trustees, sometimes the donors, and the recipient. A loan that began with discretion frequently ends with full disclosure once a recording, a competition, or a tour involves the piece.

For the private owner, the consequence is that the instrument is rarely as discreet a possession as its physical security suggests. The catalogue knows where it is; the scholarly community knows who has it; the insurance file knows the address; the performance record places it on stages whose programmes survive.

The work here is rarely to reduce the visibility, which is generally impossible without compromising the integrity of the catalogue. It is to consider, with care, how new acquisitions are recorded, how loans are described, and whether the principal's preferences for discretion can be accommodated within the conventions of a field that exists, in part, to be remembered.