The disadvantage to visiting in August is the weather - it's very hot and humid. The advantage is hotels are offering great deals, so get one in the French Quarter with a nice pool.
There is always music, but the bands change: Go to www.bestofneworleans.com and click on Music then Listings or to www.offbeat.com and click on Listings, then Music.
Note that music clubs often advertise "No Cover", meaning there is no charge for entering. However, clubs with "No Cover" often require that customers buy a beverage each for every "set" of music (which can be every 20 minutes) so KNOW THE PRICE before you sit down. Clubs do that because some people will sit in the club all evening drinking nothing (clubs only make money from the drinks they sell - not from the music). It is also a good idea to pay for each round of drinks (in clubs on Bourbon Street) as it is delivered so there can't be any confusion at the end of the evening.
About certain alcoholic beverages: Realize that some famous drinks are VERY potent compared with regular cocktails that have only 1 to 1 ½ ounces of alcohol. For example, a Hurricane is basically 3 or 4 ounces of rum in something like red Kool-Aid, and a Hand Grenade has at least 4 ½ ounces of Everclear + rum + vodka mixed with melon liquor. They don’t necessarily taste like an alcoholic beverage and it is easy to over-indulge.
Yes New Orleans is a beautiful city, and i love it. Most definately vist canal st, bourban st, and the french quarter. Jazz Gumbo, and Acme oyster bar are excellent places to eat. The Nanchez, the casino, and the cemetaries are beautiful. I stay at the marriott on canal street, everytime i go. The street performers awesome. The city park is very nice also. You may also wanna check out nola.com and neworleansonline.com for whats going on in the city....I hope you enjoy it like i do...