Information on the issue transport insurance can be found here, in the chapter 'Insurances'.
Information on musical instrument insurances can be found in the chapter 'Insurances' here.
Purchasing baggage insurance is not worthwhile in most cases because the refund is usually tied to complicated policy conditions. There is a high risk of not receiving reimbursement in case of loss or theft. In many cases, home contents insurance also protects luggage abroad.
Sometimes it can make sense for musicians to be provided with instruments at the performance location instead of travelling with their own. Pianists usually use a grand or upright piano available at the venue. Other instruments such as double bass, drums, keyboards, acoustic guitar, bass guitar or electric guitar and percussion instruments are also often supplied, since their size and weight can lead to high transport costs and renting them may be more affordable. In many countries and regions, professional backline rental companies rent out instruments by the day or for entire tours.
The term "backline" refers to the entirety of the equipment required by music groups on stage – not only the instruments but also, for example, amplifiers that can be rented locally. When ordered accordingly by the organiser or the musicians, the backline can be delivered to the concert location and set up and taken down by the rental company.