All of the unsealed vinyl here has been played on a Technics SL-BD27 turntable with KLH speakers in order to hear if there are scratches, skips, or distortion and then graded accordingly.  I have found that a record with no scratches can still sound distorted because it may have been played with an old needle that altered the grooves. 

All records are scrutinized under a 100-watt lamp so that scratches or defects will be seen.  Most times the light scratches in these records do not make the record skip, but if there were a lot of tiny scratches, it may have made the songs sound a little fuzzy or have some pop or click noises throughout.  This would then be noted.  A lot of times this 'noise' can be lessened by adjusting your treble/bass settings or cleaning it up with an audio editing software program if you are recording the tune into your computer.  

If there is a distortion or skip, it would be mentioned.  Distortion can also occur by playing it on a different turntable/stereo system, too.  If noted on the "G" grades that there is a little fuzz noise, the record may still be fine for a jukebox.  Records are graded with the below Goldmine Grading Standard in mind and I try to follow it as close as possible.

G U I D E L I N E S   T O   G R A D I N G:
Guidelines I use to rate the quality of these records (based on the Goldmine Grading Guide):

M:  Mint - Still sealed, assume vinyl is perfect.

NM:  Near Mint - Vinyl, still shiny, as if opened for the first time. No writing or stickers on the vinyl. No obvious scratches. Label: No writing or stickers and no fading of the label.  LP cover should have no creases, folds, seam splits or similar defects. 

NM-: Near Mint Minus (My grading item/description).   Similar to NM but will have some very light scratches on the vinyl not affecting the sound quality. No writing or stickers on label and no fading (or ringwear) on cover or label.

EX: Excellent - Not quite a Goldmine Standard Listing, but being used by many now. Cover: No ink wear, minor creases to corners, no seam tears. Vinyl can have scratches, but not felt by your fingers. Sound quality must be mint. No more than 15% of the surface should have wear or scuffs on it. To me, EX is like a VG++.

VG+: Very Good Plus - Similar to NM- except that on the label, there may be a sticker or writing, but it shows very little wear. There may be only a couple light surface scratches on the grooves, but do not affect the playback with noise or skips. You may only see these scratches if you put them under a bright light and really look for them. The cover might have light creasing or minor seam or corner wear, but still in great condition to show off.

VG to VG-: Very Good to Very Good Minus - May not be that shiny anymore and you will see scratches without putting it under a bright light, but they still would not affect the quality of the playback. The sound quality is still pretty good, maybe a little noise, but not enough to detract from the listening experience. The label might have some fading around it, besides having stickers or writing. The cover may have obvious ringwear in the middle or around the perimeter of where the record was, maybe some side seam splits, or little tears at the top or side where the record goes back into. If less defects, then it's a VG. If it has all this just mentioned, then a VG-.

G, G+: Good or Good Plus - It doesn't mean the vinyl is trashed. It plays though without skipping, but may have heavy noise or fuzz sound because of age, quality, or worn-down grooves. Heavy writing or stickers on the label, ringwear is very obvious on the cover and cover probably has seam splits. But, amazingly, for the vinyl, if you have special audio LP recording software, you could probably clean up those crackles and fuzzes, if you want to create a CD of it for yourself.

P: Poor - This is when the vinyl is warped to the point it warps the playback also. Or it's cracked, but it may or may not still play without a skip. If a picture sleeve is with it, this is torn or marked up big time. But someone may want to have it for nostalgia or even attempt to fix it.