They do play on 7 string but this is the 6 string version.
It's played the same on 7 string.

Tuning: Drop A 6(A-E-A-G-F#-B)
        Drop A 7(A-E-A-D-G-B-E)
|-----------------------------------------------|
|-----------------------------------------------|
|---------8-8-8--------8-8-8-5-5-5-7-7-7--------|
|-----------------------------------------------|
|---------6-6-6--------6-6-6-3-3-3-5-5-5--------|
|0---0----------0---0---------------------------|

|-----------------------------------------------|
|-----------------------------------------------|
|---------8-8-8--------8-8-8-7-7-7-11-11-11-----|
|-----------------------------------------------|
|---------6-6-6--------6-6-6-5-5-5-(b9)-(b9)-(b9)-----|
|0---0----------0---0---------------------------|

|-----------------------------------------------|
|-----------------------------------------------|
|---------8-8-8--------8-8-8-5-5-5-7-7-7--------|
|-----------------------------------------------|
|---------6-6-6--------6-6-6-3-3-3-5-5-5--------|
|0---0----------0---0---------------------------|

|-----------------------------------------------|
|-----------------------------------------------|
|---------8-8-8--------8-8-8-12-12-12-11-11-11--|
|-----------------------------------------------|
|---------6-6-6--------6-6-6-10-10-10-(b9)-(b9)-(b9)--|
|0---0----------0---0---------------------------|