Tuning:
Standard Tuning (E A D G)
Main Riff:
```
E|-------------------------|----------------------------|
A|-------------------------|-----------2222-0------------|
D|-------------------------|-------2222--------0-------2--|
G|--77---------------777---|--2222---------------2222--|
```
- Play this main riff throughout the song.
Verse:
```
E|---------|---------|---------|---------|
A|---------|---------|---------|---------|
D|---------|---------|---------|---------|
G|--777---|--555---|--333---|--111---|
```
- Play the verse riff as follows:
```
|--------------|--------------|--------------|--------------|
|--------------|--------------|--------------|--------------|
|--------------|--------------|--------------|--------------|
|---777----777-|--555----555-|--333----333-|--111----111-|
```
- Repeat this riff for the verse lyrics.
Chorus:
```
E|---------|---------|---------|---------|
A|---------|---------|---------|---------|
D|---------|---------|---------|---------|
G|-777-----|-777-----|---------|---------|
```
- Play the chorus riff as follows:
```
|--777------------|--------------|--------------|--------------|
|--777----|---777-------|--------7777-|--------------|
|---------|--777-------|--555-----------|--------------|
|---------|---------|--------7777-|------5555----|
```
- Repeat this riff for the chorus lyrics.
Bridge:
```
E|---------|---------|---------|---------|
A|---------|---------|---------|---------|
D|---------|---------|---------|---------|
G|--555---|--777---|--777---|--555---|
```
- Play the bridge riff as follows:
```
|--------------|--------------|--------------|--------------|
|--------------|--------------|--------------|--------------|
|--------------|--------------|--------------|--------------|
|---555----555-|--777----777-|--777----777-|--555----555-|
```
- Repeat this riff for the bridge lyrics.
Outro:
- Follow the same pattern as the verse and chorus, but end the song with the main riff.
Note: This guide provides a simplified version of the bass part for "Seven Nation Army." Feel free to experiment with variations and add your own interpretations to make it your own.