Your guitar’s in tune. Good. If you’re tuned to E-A-D-G-B-E, then you’re in the traditional standard guitar tuning. Great! You can play thousands of songs in this tuning. However, there are other tunings in addition to standard. And you can play thousands of songs in these tunings, too. Making Music is going to teach you how to alternately tune a guitar so you can play a wider range of music!
Have you ever wondered why your guitar is tuned with a strange combination of four fourth steps and one third? The reason mixes a little bit of history (the fact that the guitar is descendant of the lute) with some technology (the physical limitations of early guitar strings.) Standard tuning isn’t the only way a guitar can be tuned. In fact, for the beginner or intermediate guitarist, tuning guitar strings to an open chord might make more sense. It can also present endless creative opportunities for advanced players.
Although not a common method, some notable musicians and styles of music use open tuning. So if you’ve ever wanted to learn “Handsome Johnny” by Richie “Mr. Woodstock” Havens (open D) or “Honky Tonk Woman” by The Rolling Stones (open G), or if you want to play bottleneck blues guitar like Bukka White (open C), read on.
In the open tunings, your six strings are tuned up or down from their standard pitch to form a chord that sounds great just strumming the guitar without any fingering. Open tuning creates the opportunity to play unusual chord voicings, and by utilizing “drone” and “sustained” strings, strumming takes on a whole new sound. Bottleneck slide is especially popular in open tunings since the onset of blues music. Altenate tunings also make it convenient to exploit the opportunities to have bass lines, chard changes and lead lines happening simultaneously.
One thing you’ll notice with the most used open tunings—open G and open D—is that a simple index finger across all the strings now produces another major chord. To play a 12-bar blues progression, for example, simply move your barring finger up to the 5th fret and then the 7th fret. It’s a simple technique even Bonnie Raitt uses from time.
I play regularly in alternate tunings, mostly slack key style, which the Hawaiians invented in the 1800’s. The most common slack key tuning is open G, which they call taro patch. Their tunings include dozens which are not open, but can be used to produce many beautiful songs which are physically impossible to play in standard tuning. As you point out, open tunings are well suited to using a slide.