Hi All
as one with no formal musical knowledge I have come across this a few times but what is it?
Is it just another way of playing B7 or are there specifics or nuances to the chord as to where it can be placed?
cheers
ian

A 7alt chord has neither a natural fifth nor a natural ninth.

It does have a dominant seventh, but the alterations (hence the name, alt) to the fifth and ninth give it an entirely different sound than a straight seventh chord. Examples could include any or all of b5, #5, b9 and/or #9.

You see 7alt all the time in jazz fakebooks. For a jazz chart, writing 7alt is quicker and easier to read than, say, 7(#5 b9). It also gives the pianist or guitarist flexibility to use some creativity choosing which combination to play. Soloists, too. If I were stuck on a desert island with only one chord to jam over, 7alt is probably the one I would pick. It's a fun chord.

BIAB supports 7alt. You can write B7alt and it will work fine.

Matt's explained the rest, I'll just add that you are on the right track with the idea of replacing a B7 with Balt, good idea to start out by replacing "turnaround chord" which is usually going to be the V7 chord of the key, right before it returna to the root, often at the end of a chorus and heading back to the beginning.

The Tension likely won't be heard or realized until you have mastered hearing the Tritone Subs.


--Mac

Hi Matt - I think we did this before - let's do it again. There are four possible alt chords - 7b5b9, 7b5#9, 7#5b9, 7#5#9. So in my mind the alt chord is not a specific chord, but a family of chords. So I'm always wondering when I see it which of the four is being specified.

I made a BIAB song with the above four chords in C, plus C Alt, plus C Maj using PNOSIMP4 style. BIAB correctly played all, and for C Alt played a C7#5#9. So, that suggests how BIAB interprets C Alt.

So when one sees C Alt in sheet music (or fake book), how does one know what the composer/arranger had in mind, I ask. Don't say "It's up to me".

Interestingly, I just tried these chords out in PGMusic's Piano Chord Dictionary and it plays C Alt as - C E Gb G# Bb Db D#, or a composite of both # and b 5 and 9.

Don't think of this situation as being "specified" as to one particular chord out of the four.

Think of it as a "your choice" situation, governed always by the boundaries of good musical taste. (Doesn't clash with a Melody note, doesn't clash with what others may be playing, etc.)

What's neat about them is that one rhythm player could pick any one out of the four and another, at the same time, could pick one of the other three possibilities left, and most often there won't be a harmonic clash, just more added Tension heading towards the next chord or set of chords, which are the Release of that Tension.

Alt chords want to go "home".


--Mac

Kelso, Mac described very well how it works in comping. As far as your question about what the composer had in mind, I can only answer for myself:

When I compose, I generally "over-write" at first, specifying every nuance of a chord so it will be precisely the way I want it. Then I step back to see if I could instead use alt or something simpler. Usually I can, unless there is a particular melody note that requires a specific voicing without clashing, as Mac mentioned.

Otherwise, yes, it's up to you.

I don't play piano or guitar, so I try to adapt to the preferences of whomever I'm writing for. Some prefer I write the specific chord voicing, but most do not. They would rather see just a seventh chord, and they will decide whether to add the ninth, thirteenth, sharp eleven, vary the ninth or fifth, etc. I just trust to their skill and experience and get pleasantly surprised.

Hi guys
thank you all for the great info. Though I dont understand the technical aspects of it, I can see how it works.
And there was I, a poor rock band musician, thinking it meant "B7 Alternative" and me thinking " to what"? ;¬)
cheers
ian

HA! I too was a poor rock band musician...not long after the dawn of Rock 7& Roll. A time when, if you knew 3 chords, you could play every Rock & Roll song out there.

Then the 1, 6m, 4, 5 thing came down the pike so I had to add a 4th chord.

Then the Beatles came along and ruined my career!

Ab7sus??? Dbmaj7/F???? SERIOUSLY???

(-:

Jim

A rocker? If you play guitar, you surely know the "Jimi Hendrix Chord" (Big use in Purple Haze, but I think Wes Montgomery beat Jimi by about a decade with this chord .) It's an E7#9 but Jimi (and Wes) don't play the 5, so it's a perfectly fine alt chord.

E-G#-D-G. You are using the inside 4 strings with the E on the 7th fret.

My go-to alt chord!

Everything said sounds correct to me.

To add to the discussion:

An alt chord is primarily used to create tension. The dominant chord when it has a dominant function already creates tension and makes ones ear expect and/or enjoy the resolution (generally to a chord a fifth below and often to the tonic). Adding the altered notes to a dominant 7 chord increases the tension and the subsequent sense of resolution.

One way of thinking of it is that the altered chord is made up from the notes of the altered scale (the altered scale also creates tension). The altered scale is made up of the:

1 b2 b3 nat3 b5 #5 b7, or another way and probably better way to write that is by using these enharmonic equivilents:

1 b9 #9 3 b5 #5 b7

If you start with the 1 3 b7 for your dominant chord, you can then add any one of those other notes or more than one of those other notes to create an alt chord.

C7b9 C7#9 C7b5 C7#5 C7#5#9 etc. All of those are altered dominants derived from the altered scale.

And a great choice of a scale to play over any on those dominant altered chords is the, you guessed it, the altered scale. In the case of those C7alt chords listed above.

1 b9 #9 3 b5 #5 b7 or C Db D# E Gb G# Bb

Also, the altered scale is the seventh mode of the melodic minor. In other words the C altered scale is the same group of notes as the Db melodic minor scale.

(Perhaps more than most would want to read or as Zappa would say, "Shut up and play your guitar")

That is really good teaching, Frankp!


--Mac