Generally if you were using this AA you would have a variety of bonds: muni, investment grade commercial, maybe junk bonds (lower rated bonds) and even Treasure bonds. These bonds can be short term or long term. This could be a bond fund or you could buy individual bonds if you have a large enough portfolio. You certainly wouldn't want to buy just one or two individual bonds. Bond funds can be very broad or focus on one time of bond and duration (e.g., short term California muni fund).
IMHO it would be folly to put 60% of your portfolio in bonds at this point. Over the last 30 years bonds have done great. That's because interest rates have been drifting downwards. I think pretty much everyone believes that over the next 10+ years that interest rates will climb. Maybe not next year or even the year after, but soon. When interest rates climb the value of your bond will decrease if you have to sell early.
Let's say you bought a $1000. bond at 4% and interest rates climb to 5%. No one is going to pay you face value for your 4% bond. They are going to want to pay you less so that they will reap 5%. I believe that the rough estimate is that if interest rates rise 1% then the value of your bond will go down by 10% for each year. (I may be remembering that wrong and I'm too lazy to look it up.) If you hold the bond to maturity then you will still get your $1000 back.
I would go for a portfolio much lower in bonds. I'm retired and keep about 15% in bonds (it use to be 20% and will derop more when a bond matures in August.) I'd up the stock and maybe even cash %, and look at REITS. I'd keep my bonds short-term.