Amazon.com - Tuner Machine Head 4-String Open Gear Bass Tuners Tuning Pegs Keys Machine Heads for Bass Guitar (Color : 4R Black)
Cort GB Series Modern 4-String Bass Guitar Open Pore – Ploutone
Have you tried B-E-A-D tuning on your 4-string bass? | eBass
Glarry 4-String Bass Guitar Kit for Beginner with 20W Amplifier, Black - Walmart.com
How To Tune A Bass Guitar? Easy Step By Step Methods, 60% OFF
Bass guitar tuning - Wikipedia
Amazon.com: Donner Electric Bass Guitar 4 Strings Full-Size Standard Bass PB-Style Beginner Kit Black for Starter with Free Online Lesson Gig Bag Guitar Strap and Guitar Cable, DPB-510D : Musical Instruments
Tuning a bass guitar using 5th Fret Method - Get-Tuned.com