After many years of paying without looking around, I have transfered my policy from Allianz to New Moon. For me and my specific requirements they were over 45% cheaper and there were several options for cover level (eg UK / EU / Worldwide, car cover or not etc etc).
Have a look https://www.newmooninsurance.com/musical-instrument-insurance?gclid=EAIaIQobChMIpf6pnITM5gIVhrHtCh0YdwEOEAAYASAAEgKutPD_BwE