In my mind, a "cover band" plays other people's songs.
A "tribute band" attempts to duplicate the sound of the original recording.
A "band" implies more than one person, which is a solo act.
I am going to assume we are discussing the former. The latter is thin on the ground around here.
Free Harmony is a duo, they play mostly covers and sometimes other locals sit in with them. Chuck sings and plays acoustic guitar, Sharon sings and plays percussion and keys.
They have stellar harmonies/counterpoint. I love listening to them.
The Pennystinkers is a duo, a 3 piece and a 4 piece depending. Jeff on lead vocals and acoustic guitar, JD on bass and harmony vocal is the core of the group. They will add Michael on vocals and lead guitar and various drummers depending on the club's budget. They have a loyal following and always fill the dance floor with any configuration they bring. Tight and fun.
Spaceband plays 90's hip-hop style stuff, the drums and bass are LOCKED tight. Singer knows ALL the raps and is very charismatic. Another dance floor filler, great band.
JP Falcon Band (disclaimer - I am in this band) Falcon is one of the busiest musicians in our area and an incredible singer with a huge repetiore. No set list, not even a list of songs, all in memory. We take requests and learn them on the spot pretty often. Duo (with me on guitar and vocals) or we add drums/precussion and/or bass if the room and budget allow. If I wasn't in this band I would go see them!! It's an honor and a joy to play with these musicians.
If I think of more I will include. There is more music going on here, lots of originals, lots of styles. Fairly small city - 90,000 but we punch beyond our weight.