Merge branch 'master' of https://github.com/Microsoft/pxt-microbit

docs/getting-started.md

@@ -234,7 +234,6 @@ Here are the blocks to make your coin flipper.  When you press button
 on the LED screen.
 
 ```blocks
-basic.forever(() => {
 input.onButtonPressed(Button.B, () => {
     if (Math.randomBoolean()) {
         basic.showString("H");
@@ -242,14 +241,12 @@ basic.forever(() => {
         basic.showString("T");
     }
 });
-});
 ```
 ### ~hint
 
 The ``pick random true or false`` block randomly tells the ``if``
-block `true` or `false`.  If the ``pick`` block
-picked `true`, the ``if`` block shows the letter `H`. Otherwise, it
-shows the letter `T`.
+block `true` or `false`.  If the ``pick`` block picked `true`, the
+``if`` block shows the letter `H`. Otherwise, it shows the letter `T`.
 
 That's it!
 
@@ -280,7 +277,6 @@ show your score.
 When you're done, your coin flipping program should look like this:
 
 ```blocks
-basic.forever(() => {
 input.onButtonPressed(Button.B, () => {
     if (Math.randomBoolean()) {
         basic.showString("H");
@@ -294,7 +290,6 @@ basic.forever(() => {
 input.onButtonPressed(Button.AB, () => {
     basic.showNumber(game.score());
 });
-});
 ```
 
 Flip until your thumbs get tired!

docs/reference/music/change-tempo.md

@@ -1,10 +1,11 @@
 # Change Tempo By
 
-Change the tempo by the specified amount
+Makes the [tempo](/reference/music/tempo) (speed of a piece of music)
+faster or slower by the amount you say.
 
 ## Simulator
 
-Simulation of this function is available in many, but not all browsers.
+This function only works on the micro:bit and in some browsers.
 
 ```sig
 music.changeTempoBy(20)
@@ -12,7 +13,21 @@ music.changeTempoBy(20)
 
 ### Parameters
 
-* `bpm` : [Number](/reference/types/number) - change the tempo by beats per minute
+* a [number](/reference/types/number) that says how much to change the bpm (beats per minute, or number of beats in a minute of the music that the micro:bit is playing).
+
+### Examples
+
+This program makes the music faster by 12 bpm.
+
+```blocks
+music.changeTempoBy(12)
+```
+
+This program makes the music _slower_ by 12 bpm.
+
+```blocks
+music.changeTempoBy(-12)
+```
 
 ### See also
 

docs/reference/music/set-tempo.md

@@ -1,14 +1,17 @@
 # Set Tempo 
 
-Sets the tempo to the specified amount
+Makes the tempo (speed of a piece of music) as fast or slow as you say.
 
 ```sig
 music.setTempo(60)
 ```
+## Simulator
+
+This function only works on the micro:bit and in some browsers.
 
 ### Parameters
 
-* Returns : [Number](/reference/types/number) - sets the tempo in beats per minute
+* a [number](/reference/types/number) that means the bpm you want (beats per minute, or number of beats in a minute of the music that the micro:bit is playing).
 
 ### See also