Slash cords

Slashes in chord names indicate that the second note should be played as the bass (lowest) note, I read them like:

Am/C# = "A minor chord with a C sharp in the bass".

Lots of these result in interesting altered sounds for chords. The other option is to simply play the (unaltered) chord, and have a bassist you're playing with really emphasise the bass note.

It might be a typo in the original post, but D/Am is not a slash chord.

'Slash' chords, as oldiron noted, have the chord first, and the bass note second. D/Am may be reversed - intended as Am/D. If it's really D/Am as written it's called a polychord... a different animal entirely.

Polychords are combinations of two different chords occurring at the same time. They're usually seen only in jazz charts, but I've seen a rare use of them in other types of music. If you have two guitarists, one would play the D chord, the other the Am chord.

If you're playing solo, you need to figure out what the result is:

D=D-F#-A
Am = A-C-E

So you'd have D-F#-A-C-E, which is a D9 chord.

You probably wonder why they don't just write D9, huh? There could be several reasons...

1. D9 is a five-note chord. Many guitarists playing complex chords will simplify them to be four notes. In this case you might play D-F#-C-E, and you'd have all the elements to make it sound like a ninth - but maybe including the A is very important to the composer. Triads don't get simplified, so writing D/Am ensures all notes get played.

2. The guitar only has six strings. If one or both sides of the polychord is a 7th (or 9th, etc.), the result with two guitars will be seven or more different tones.

3. When faced with polychords, the two guitarists will often play in different registers. This gives you a result with a very large span between the lowest and highest notes. For instance, if the Am is played open, and the D is played at the 10th fret, you'd need at least a 6-fret reach to hit the highest and lowest notes on one guitar.

4. Maybe the tune was written by a person(s) who knew very little about guitar chords, but the sound they wanted was created by combining two chords he/they knew... in that case, maybe it's a polychord, and maybe it's a 9th.

Sorry Noteboat,
I didn't have the music that I was questioning handy when I was forming the question. I think it's more of the case undercat is refering to, the cords are showing up in sixties and sventys pop/rock music.

So if I have this correct I would finger the first indicated cord and play the second (indicated) note as the bass note. That would make sence, a lot easier than trying to figure out polycords that noteboat talks about. Sounds like something a jazz player would come up with to drive "lesser players" crazy.

I believe you strum the chord and the bass note at the same time. Please correct me if I'm wrong.

you are correct.

Or even more commonly, the guitarist plays the chord and the bassist plays the bass note.