Companies can have lots of logos. Usually, the corporation will have a logo, with each brand (product) that the company sells having a logo of its own as well. This makes a certain amount of sense. Sometimes the company wants to distinguish itself from its products (especially if one of those products isn't selling well).
However, seldom do products have more than one logo. Remember, a logo is the brands identifying feature, its "birthmark" if you will. Seeing a logo should invoke an emotional response toward the product. The logo should make you salivate, thirst, or desire that product, much like seeing the prominent characteristic of someone makes you want to... well, say hi. The point is, having more than one logo is just plain confusing.
Now, that isn't to say that the logo can't have a few variation. Everybody ("thing") likes to dress up for special occasions, and of course styles and tastes change (my poor long lost mullet). But the core elements of the original logo will be found in all of its alternates.
However, the Utah Jazz have two distinct logos. A Primary "mountain" and a secondary "note" logo. The "mountain" logo has been recolored three times in the past 20 years, trying to find its place in the organization. However, starting in 2010, the Jazz began promoting its "note" secondary logo more than its "mountain" primary one.
Current Primary Logo
Current Secondary Logo
This has lead to some confusion. Have the Jazz changed logos? Did they move? Can I still wear the jersey I purchased last season? But the most confusing question of all is..."why confuse your fans in the first place?"
My dad uses the phrase "follow the money" any time something doesn't seem quite right. And in this case that is exactly the reason for the confusion. The league charges each franchise a logo change fee. Its expensive and time-consuming for the League to change a teams logos. Signage, promotions, jersey's (contracts) all have to be updated. So the NBA has a two tiered "fine" schedule to make each change "hurt." When the Jazz brought back the "note" logo in 2010,
they kept the "mountain" logo as their primary one mostly because of the fine they would have to pay to change the entire logo. The league charges a smaller fee for simple color changes.
The result is that the Jazz have been using the logo they want to use, but its not the "official/primary" logo of the team. With changes to the rules regarding how the team can spend its money (due to the lockout negotiations) the Jazz can now complete its five (plus) year transition back to a logo similar in design to what was used in the 1995/96 season.
Other teams that have secondary logos:
Brooklyn Nets
Golden State Warriors
Houston Rockets
Miami Heat Secondary
New Orleans Pelicans
Phoenix Suns
Washington Wizards
For the full KSL news article with images.
http://www.ksl.com/?sid=35632429&nid=294&fm=home_page&s_cid=toppick1
For a look at the past logos and the research material for the list of secondary logos.
http://www.sportslogos.net/logos/list_by_team/234/Utah_Jazz/