So, you've mangaged to tune your ukulele, you're holding it properly, you have your left ring finger placed to make a C chord, and your right index finger is extended, nail facing down... You are ready to strum! Strumming is the rhythmic component of the ukulele, and for the rest of the beginner's series of uke lessons, we're just going to strum.
Because metronomes are boring, and teach you nothing about tonality, UkeSchool.com is built using interactive jam tracks that allow you to develop good, rhythmic strumming habits. There is nothing like playing with a real band, but from a learning standpoint, playing with a fake band comes pretty close.
You may be tempted to rush ahead and play faster or fancier things, but you should imitate my slow plodding ukulele track until we've re-wired your brain a bit more. You might notice that I made some sloppy strums when I recorded that - let that be a lesson - don't worry about a couple of sloppy strums. Just stay with the song.
The 'slashes' are something you will encounter in written music as well, they mean, "the same as before". Sort of like "ditto marks". The blue indicator that moves across highlights each bar as it plays - a bar, when strumming in this style is down-up-down-up-down-up-down-up. (4 of them). 4 Beats to the bar. 4 bars to a 'phrase'. 16 down strums, 16 up strums, and then it all starts all over again. All music falls into patterns like this, so it is good if you can get comfortable with paying attention to patterns whenever you encounter them.
In formal music education, they would have you count "One and two and three and four and" while you strum. Try it! It will help synchronize all the neural pathways in your brain. You will benefit from the practice when we start to waltz, and you only get to count to 3.
We've started with a very slow, simple, 'jug-band' groove, to get you started. How did it feel? Was it a thrill to be playing along? Don't worry, it gets more fun when the songs are actually songs. Play along with it as long as you feel like, and try to stop thinking about the ups and the downs and when they are supposed to happen. Try to feel natural, instinctive, at ease with it, like clapping along to a song. When you feel like it isn't something you have to concentrate on too much, move along to the next lesson.