The four guitars were taken by burglars who forced open the door to a basement flat between 7.45pm and midnight on Tuesday, 8 July.
All were in cases – three black and one grey – and a large rucksack was also taken.
PC Heather McDonald said: “Someone may have seen the instruments being taken out of the house or could have seen them offered for sale.
“They are quite distinctive so if you see them or saw anyone acting suspiciously in the area please contact us.”
Sussex Police launched Operation Magpie to tackle burglary across the county.
Anyone with information should call 101 quoting serial 33 of 09/07, email firstname.lastname@example.org or call the independent charity Crimestoppers anonymously on 0800 555111.