Searching for "45 record" brings 650,730 results. Searching just music only reduces it to 648,063. Using "Refine Search" on the left hand side of the page for records still reduces it to only 646,584 but clicking Genre or style of music brings it to varying quantities like:
Blues (5,849) - Children's (1,575) - Christian & Gospel (3,328)Classical (1,421) - Comedy (1,461) - Country (48,789) - Dance, DJ & Electronic (18,867) Easy Listening (6,294) - Folk (2,843) - Holiday (1,650) - Jazz (10,008) - Latin (2,681) Metal (1,860) - Pop (78,200) - R&B & Soul (118,036) - Rap & Hip Hop (1,901)Reggae & Ska (14,175) - Rock (192,822) - Soundtrack & Theater (4,803) - World Music (9,532)
Using Boolean search methods specifically for "45 record" drops it to 11,538 but you only find listings where the seller has used those exact terms. If I listed an artist and song names that used up my 55 characters in the title bar, I might not be able to use "rpm speed" or term "record", so you would miss them. (something to consider when listing)
Instead, try clicking more qualifiers. In the music category you can narrow it down by Record Size 7" (563,615), 10" (1,392), 12" (36,223), Not Specified (32,659)
Condition New, Used, Not Specified
Duration Single (521,009), EP (30,428), LP (6,913) etc
Special Attributes like Promo (26,968), Import (21,336), Colored Vinyl (6,038)
Speed 16 RPM (1) 33 RPM (4,821), 45 RPM (633,457), 78 RPM (109)
Seller eBay Top-rated sellers, Specify sellers...
Buying formats Auction, Buy It Now, etc
Location US Only, Choose more Location...
Distance from you Enter miles from your Zip code
Of course, if you are not just "window shopping" and know the specific title then put that in and see what you get. If too many, then use the Boolean quotation marks around the title or artist. Boolean techniques are not forgiving and eBay's search is not as intuitive as Google so in most cases, what you type is what you get. If you suddenly end up with nothing, you probably misspelled something so take your time.
There are more things you can do when searching on eBay to find your item or to find deals, but maybe you have tips to share?