# Tutorial 5: Referencing Player Attributes

You can set variables outside a player

``` python
pitches = P[0,1,2,3,4]
harmony = pitches + 2

print(pitches)
print(harmony)

p1 >> pluck(pitches)
p2 >> star(harmony)
```

If you set the duration of the second, it might not have the desired effect

``` python
p1 >> pluck(pitches)
p2 >> star(harmony, dur=1/2)
```

It is possible for one player object to play exactly what another player is.
To have one player follow another, just use the follow method:

``` python
p1 >> pluck(pitches)

p2 >> star(dur=1/2).follow(p1) + 2
```

You can explicitly reference attributes such as pitch or duration too:

``` python
p2 >> star(p1.pitch) + 2  # this is the same as .follow(p1)
```

Works for other attributes too

``` python
p1 >> pluck(pitches)
p2 >> star(dur=p1.dur).follow(p1) + 2
```

You can reference, and test for the current value
The `==` returns a `1` if True and a `0` if False

``` python
print(p1.degree)
print(p1.degree == 2)
```

This allows you to do conditionals like

``` python
p1 >> pluck([0,1,2,3], amp=(p1.degree==1))

p1 >> pluck([0,1,2,3], amp=(p1.degree>1))
```

Or change it to a different amp by multiplying by 4

``` python
p1 >> pluck([0,1,2,3], amp=(p1.degree==1)*4)
```

Chain multiple conditionals

``` python
p1 >> pluck([0,1,2,3], amp=(p1.degree==1)*4 + (p1.degree==2)*1)
```

Which is the same as

``` python
p1 >> pluck([0,1,2,3], amp=p1.degree.map({1:4, 2:1}))
```