What's not really clear there is the fact that ALL bard haste songs, except the Ervaj, Vah Shir and Rizlona's are considered considered spell haste. Those are commonly referred to by bards as "overhaste songs" because they give you a small amount of haste AND allow you to go over the haste cap for your level by a certain percentage. As is stated in that blurb though, sometimes bard haste songs will still show the icon when you have chanter/shammy haste on. This is due to the fact that those haste songs also usually have stat buffs to them, such as increased strength, agility, or armor class. You will still receive those stat increases, but only the higher spell haste, so sometimes bards will still play that song. When a bard is involved, I suggest letting him/her decide what song is best for the situation, since they SHOULD know what their songs do. If they're swearing up and down that their haste stacks with shammy/chanter haste before level 47 (I believe that's when we get our first overhaste, can't remember off the top of my head) then you'll know they either don't know what they're talking about or they've been completely misinformed.