Hi, the question is in the title of the topic, I have a backing track that I really like but it is in Dm. I’m used to play my C harp over a backing track in G so I don’t which harp to use here. I don’t know ANY-THING about music theory so I wouldn’t mind a little explanation here.
Also : what is the difference between D and Dm for example, am I supposed play differently (I improvise over the backing track).
You must always play/improvise in the minor key when the song or backing is in a minor key. For music backing in a major key you can play/improvise either that in that major key or in the minor key depending on the mood/feeling you wish to express – you can even mix the major and minors!
So for music in D minor there are two popular choices (there are also more, but I hope to keep this sort of simple): play your C harp in 3rd position (which is D minor) or play a G harp in 2nd position (where you can play either D major or D minor without too much difficulty). The C harp in 3rd position is your easiest choice.
If you need more info about 3rd position, Jason Ricci has several good YouTube video lessons, and I am sure that Luke @Luke also has at least one on the forum’s YouTube channel.
Trying to explain this all in forum posts to someone (meaning you) who does not know anything about music theory or the differences between major and minor is a lot of work!! Therefore I point you to those YouTube lessons.
Regards,
– Slim 
Thank you ! I’m going to look this up, also, can you explain / give me a video that explains exactly what positions are (first second etc.) ? I have a vague sense of what it is but I’m really not sure.
You are very welcome!
Again, for your question concerning harmonica positions (of which there are 12 – but only 6 are really used very much), I refer you to the YouTube pages of Jason Ricci and Luke @Luke. However, if you use the search function you will find posts from Luke @Luke and myself that describe and discuss harp positions.
Regards,
– Slim
thanks a lot ! I will look into this
A lot of really good information has been provided for using major key harmonicas against a minor backing track.
Another possibility, when you want to try it, is to get natural minor harmonicas. Whether you prefer Suzuki, Seydel, Hohner, Lee Oskar, etc., they each offer harps in minor keys. A pleasant and slightly different sound.
The replies make it sound like you need to learn more music theory, but for this question you do not and it is really simple.
To play any minor key, pick the major key harmonica one note up and play it 3rd position. SIMPLE (once you learn the 3rd position)
So for Dm play your C harp 3rd position. For Am play your G harp. On an A major harp, third position is Bm. Got it?
Hi @mauraulucien - the 2 easiest ways to play minor are 3rd position, as other folks have mentioned, or to buy a Natural Minor harmonica which are tuned to pay 2nd position and sound minor.
If the backing track is on YouTube, please provide a link and that would help to to tell you which of these options would likely sound better.
As @BnT mentioned, you can play minor on a standard harp in 2nd position, but this requires really good control of the -3’ bend and so is a bit challenging.
As @argold57 mentioned it’s very easy to figure out what harp you need for 3rd position, just up one letter name, so your C harmonica is good for Dm. Here’s the scales:
That quote comes fro this post:
By contrast, here’s a post showing what the Natural Minor harmonic sounds like:
thanks for the advice ! I had moved on on something else but I’m going to try it.
Unfortunately no, the backing track is not on YouTube, I have a MP3 recording of it and I don’t know if I can post mp3 files here.
Seems like people can share via dropbox? You could play it and shoot a video of your computer for 30s and then upload it to YT and share that?
Or you could just email it to me at Luke@harmonica.com.
Keep me posted here if you have any other questions on the subject.
Just posted it on YouTube as you suggested ! 
That’s a nice little backing track.
I personally would use my C blues harp and play it in 3rd position (which lets me play the Dm scale). The root (or “home”) note is D (which is -1, -4 or -8 on your C blues harp). The 3rd position Dm pentatonic scale is one of the easier ones to play and only has one difficult note (the 3 draw two-step bend: -3") and one semi-difficult note (the 2 draw two-step bend: -2"). Luke @Luke gave you the Dm pentatonic scale tabs for the mid-range on your C blues harp because it does not use any bent notes. Here is the full 2 octave range of the Dm pentatonic scale on your C blues harp:
-1 -2" -2 -3" +4 -4 -5 +6 -6 +7 -8
You can also play +1 at the low end and above -8 you can add -9, +9, -10 and +10. The “wailer” note (as Jon Gindick calls it) is found at -3", -6 and -10. You can add other bends to this scale for even more emotional, “bluesy” effects, but I will leave those for you to discover as you “make friends” with this 3rd position.
It is also possible to use a G blues harp played in 2nd position (like playing your C blues harp in 2nd position over a backing track in G). But since you have a C blues harp and 3rd position is very useful to learn, I would suggest giving it a go with your C harp – I’m positive that you will not regret it !! 
Regards,
– Slim
OK @mauraulucien COOL! Thanks for posting this. Really cool jam track!
Yeah so all of @Slim’s advice is great. 3rd position is a wise and fun investment of time.
I’m gonna offer another perspective here. This tack is a PERFECT example of a tune that really lends itself well to a Natural Minor tuned harmonica.
The reason why? It’s a true minor blues:
If the IV chord were major, like on the song Messin’ with the Kid or like Oye Como Va which is in one of the links in my previous post on the thread, 3rd position lends itself particularly well in those kind of contexts.
I’m gonna spit out some jargon here, but stick with me here, even if some is Greek.
In 3rd position, when you play the minor scale in the middle octave:
-4 5 -5 6 -6 -7 7 -8
You are playing what’s known as the Dorian mode.
Dorian is the same as Natural Minor BUT the 6th scale degree is raised.
The 6th degree of a scale is important when you go to the IV chord, because it is the 3rd of that chord, and thus will dictate whether that chord is major or minor.
So on this jam track, when you go to the iv chord, you will have to avoid the -7 as it will sound sour.
Now, while it’s true that if you’re just playing pentatonic or blues scale stuff then this is irrelevant, you’ll find that on a Natural Minor harmonica you don’t have any avoid notes. (And it’s fun to play minor scales on minor blues)
MORE IMPORTANTLY, on a Natural Minor harmonica you can play CHORDS!
And this Blues track has what they call “a Quick IV” which means the 2nd bar of the form goes to the iv chord. So you’re getting some iv chord in every phrase:
You’ll find it’s really fun being able to play chord in those places, and to know that anywhere you blow on the harmonica will sound very consonant with that chord.
Finally, this song also has a minor v chord, which you can also play on a natural minor harmonica -456
So if you love playing with this track, and you’ve got some extra dough, it’d be a perfect opportunity to dip your toes into a Dm Natural Minor tuned harmonica.
Remember, Natural Minor harmonica’s are labeled in 2nd position. So a Dm harmonica is gonna be in the same range as a standard tuned G harmonica.
You can get a Lee Oskar for around $50.
I just bought a Joe Spiers Custom Custom Special 20 Natural Minor harmonica for a meager $250! (But worth every penny for me personally!)
Hope that helps!
Thanks to both of you ! There is a lot to take in so I will take my time here. I could eventually buy a Dm harp but will it be useful in other situation ? Because I don’t know if I’m willing to spend 40€ for a harp that I will use only to play over this specific backing track.
I found this by searching “lee oskar natural minor D harmonica”, is it the one that you were talking about in your post ?
If you like a bit of slow noodling? Is that the right term?
I like this one. It’s C#m. So I use a B harmonica. It’s a nice one to practice dropping in and out of rather than playing the whole time. “Putting holes in it”.?
@mauraulucien Yes! That is the correct one. I don’t know if it’s worth buying that harp just to play over that jam track. Tough to say. It’s fun to have a Natural Minor harmonica, but Dm is a pretty low key. Em, Gm, or Am is probably more fun and would probably get more use over time.
@toogdog ooooh that IS a really fun track to play over on a B harmonica and thinking about it from a 3rd position perspective works really nicely.
Interestingly you could say that song is in C#m but it might be more accurate to say E major (they’re the exact same notes, just calling different note of the scale the root - that’s why we say E major is “relative major” of C#m, and vice versa C#m is “relative minor” or E major.)
So I hadn’t noticed this before, so I thank you for sharing this and thereby bringing it to my attention: playing 3rd position minor as playing in what’s also called 12th position (but I recently learned many people refer to it as “1st flat position” because it’s one space to the left on circle of 5ths chart.)
@Slim might dig this turn in the conversation. Lots of people are intimidated by 12th position because the root is -2", but if you’re comfy with 3rd position, that can kinda remove some of the fear of exploring 12th position.
Similarly, playing the minor scale in 5th position can feel intimidating, but if you know your 2nd position major pentatonic scale, it’s the exact same notes as the 5th position minor pentatonic scale.
BTW - this Glassy Surface track you shared @toogdog would also be a great candidate for playing a C# Natural Minor harp. It’s another example where the tonality is truly a natural minor rather than Dorian sound.
It actually works great for me because I’m using Parrott-tuned harp with the -7 tuned down a half-step, which makes 3rd position a natural minor (rather than Dorian) kinda sound. And of course you can that note in the lower octave playing -3’ instead of -3.
I know I’m probably speaking Greek to many here. Can’t help myself. Wind me up and watch me go. 