Just got this question in from a course participant. I know it is on the mind of many players, so here is a blog post answer, basically to the question: What is the role of intervals? Or, as I hear these questions and similar ones sometimes: Why learn intervals? How do you understand the role of intervals in the learning process? Here my reply. 

Why Learn Intervals?

I understand the role of intervals in the learning process as follows.
Intervals are…
1 – Shapes (you can move shapes around all over the fretboard if you know how. All of a sudden, the inherent organization of the fretboard makes more sense!)
2 – Sounds (If you know/practice intervals, you know what two or more notes will sound like, what effect that has… for example: “A minor third laid over a dominant-7 chord sounds bluesy.”)
3 – Functions and sounds in a chord progression (A musician may call out the changes to you, “hey, it’s just a 1 – 6 – 2 – 5”)
4 – Material to create grooves from when you see a chord progression: C Am Dm G (that’s that 1 – 6 – 2 – 5 again, here in the key of C!)
5 – The smallest building blocks in our tonal system and a way to categorize, name and communicate sounds, ideas etc.
6 – Want to learn to read music? If you know your intervals on the fretboard, reading music is so much easier!
7 – Also: Anything remotely intermediate or advanced in music or music theory will use intervals for communication: scales, chords, melodies. All made up of intervals. If you do not understand intervals at the very base, everything else will be too hard. Frustrating. And it will not make sense.
8 – To really understand intervals and understand them on the bass, you need to use them. Best creatively. Best by jamming. As you say you got a good ear for the bass. In the course you will be doing those “Creative Note finders” that are incorporating intervals soon. Make it conscious, what you are practicing there: finding the note(s) of the week, and then using the intervals as described. Major second up. Minor third down, etc. All over the fretboard! Do them over and over. Until not only the note(s) of the week, but also the interval(s) we practice with them become second nature. That’s why we usually have a major and a minor track for this each week. Being comprehensive, we go through all 21 notes!
A lot of methods and books glance over that practicing bit – especially classical music theory books (plus, they are not directed toward electric bassists). A lot of books say: “Here, this is a third right there on the staff. Got it?” And leave it at that. This misses an immensely important step – to actually practice it, hear it, use it in a groove, so you understand it, not just intellectually, but with your whole being! In all areas of the bass. On every string.
9 – Song learning and memorization. If you can identify and name intervals and all that is built from intervals (chords, keys, melodies etc) then you will start learning in chunks: Oh the first bar is just arpeggiating a C major triad, and then it goes to the five chord (that is Ob-La-Di, Ob-La-Da by the way). You will reference sounds to shapes and names – which will make remembering songs more effective.
10 – Eartraining. You say you have a good ear and I am certain you probably are intuiting a lot of intervals, chords etc, without knowing the names for things. Categorizing sounds and giving them names makes them clearer and conveniently communicatable.
I could keep going. But I struggle with the fact that some of this cannot be explained until you have done it on the fretboard. Understood it. Heard it. Played it. Once you listen to a random piece of music and go, oh, the bass player is starting on the third, s/he is playing a first inversion chord there. Ah, that’s that gospel progression again, where you go to the “3 over 1”. Got it.
The freedom from being able to identify, use, communicate and creatively put musical building blocks all over the fretboard, no matter where you are, is inspiring and builds confidence in your skill. And it all started with intervals 😉
Hope this helps. Keep going and enjoy the ride!
Ari