A lot of 10k projects boast that they have between 160 and 200 traits. However, on its own the Lute musical influences trait contains 141 items!
Between genre, instruments, influence, vehicle, venue, and rider there are close to 460 individual traits. But we didn't stop there.
Each major trait category (Genre, Instrument, etc…) has a rarity likelihood which is set at a 60% chance of getting a "common", 30% chance of getting a "mid", and 10% chance of getting a "rare". On top of that, Instruments and Vehicles also have a small chance of securing either a randomized Suffix or Prefix + Suffix combo.
In total there are 36 suffixes (e.g. of Power) that may be added, based on a randomized chance roll. Your chance of getting a Suffix on any one of the four traits that can accept Suffixes (3 Instruments + the Touring Vehicle) is 6 out of 21, or ~28.5%.
You have a ~9.5% chance (2 out of 21) of rolling a Prefix + Suffix combo. There are 31 Prefixes that may be added to either an Instrument or Vehicle in random combination with a Suffix to form these combos, Groovy School Bus of Love for example.
In short, you are much more likely to get a Suffix than a Prefix + Suffix combo.
The percentage chances are run on a per attribute basis. This means that while a single Instrument has a ~9.5% chance of getting a Prefix + Suffix combo, the likelihood of two of your instruments getting a combo is much smaller, and the chance of all three of your instruments hitting a combo is extremely unlikely. The chance of all three Instruments plus your vehicle hitting the Prefix + Suffix combo is tiny.
Here's where things get really interesting.
Because you have a 10% chance of pulling a "rare" Instrument or Vehicle trait, the likelihood of getting one of the "rare" Instruments/Vehicles with a Prefix + Suffix combo is a lot smaller than pulling a "common" or "mid" Instrument/Vehicle with that combo.
Let's use Band #69 as an example. Not only does it nicely show off everything discussed above, it is always a solid number choice for any project.