Hey Silvia … 3rds & 6ths are simply intervals but grouped together to make melodic lead lines or rhythm parts.
I wrote about 3rds here: 3rds & Thirds - What Are They? Playing & Having Fun
I was sure I had a topic on 6ths too … did I not remember to update it and migrate it from the old forum before it closed and we all moved here? Mmmh. Maybe I need to get looking into that.
