Leaving aside a blatant error in the sub-title (roaring 20s yes, but the 30s were the depression era), this is a fascinating and fantastic collection. Many of these songs have stood the test of time well.
As with all music this old, it cannot be technically perfect. Some tracks have crackles and hiss, but this is often how these records sounded to listeners back then. When recorded music was a novelty, people tolerated the imperfections. If you must have perfect sound quality, don't buy music this old.
There are more recent covers of many of these songs, and the compilers have included some here, which emphasize the limitations of the original ancient recordings. I like the Puppini Sisters and the Temperance Seven, but while these 20s/30s revivalists have made some excellent music, I have mixed feelings about their inclusion here. Still, if their presence means more people discover the original music here, that's a good thing.
There are other less obvious llater covers too, including the Ella / Louis cover of Dream a little dream of me, which they recorded in 1950. This song dates from the thirties, but was revived in the sixties, first by the Shirelles and later by Mama Cass.
Despite some songs being later covers, most of the recordings are genuine recordings from the 20s and 30s, which capture the spirit of the music superbly. I'm glad that Helen Kane's version of I wanna be loved by you was included despite the crackling. I like Marilyn Monroe's cover, but Helen's presence here reminds me to look for some of her own music, hoping that some of it has survived with fewer crackles.
Whether you are just getting curious about this type of music or you have some already as I do, this is an excellent compilation.