How many different vocalists are featured on the CD ?
Caution: Often, the "showcase" vocalist is the only member of the band with credible vocal ability. A band may have 4 vocalists, but 3 may only be capable of singing backup.

Does the vocalist do a reasonable job of preserving the sound and feel of the original recording ?
Caution: The tonal quality and phrasing of the vocal can determine if a song sounds authentic. A singer with a voice like Sting's will not cover a song by Elvis Presley credibly. A vocalist with a voice like Aretha Franklin's should not perform a song by Frank Sinatra. But we have heard unfortunate examples like this on many demo CDs.

Are there more instruments and vocal parts on the CD than the number of musicians in the band ?
Caution: We have heard many CDs with two guitar parts magically being played by a single guitar player, female vocalists who miraculously sing lead and background simultaneously, and extra horns added to a recording to "fatten up" the sound. Unfortunately, you won't hear those "extras" when the band plays at your event. Many bands figure that you will be too busy on the night of your party to notice what is missing.

Does the song make you want to dance (or play the dashboard, if you're listening in the car) ?
Caution: If this isn't the case, your guests probably won't be too enthused, either.

Does the keyboard player, bass player, or drummer serve as one of the horn players in the band ?
Caution: If this is the case, a key instrument will be missing when they play the horn. Often, bands use karaoke-like programs to play the missing parts, usually with mediocre results.