The numbers will be formidable when Def Leppard, Journey and the Steve Miller Band perform Friday night at Petco Park in downtown San Diego.

All three bands have been inducted into the Rock & Roll Hall of Fame (Miller in 2016, Journey in 2017 and Def Leppard in 2019). Between them, they will perform nearly 50 songs (12 by Miller and his band, 16 by Journey, and 18 by Def Leppard, which headlines).

Miller will perform for an hour, while Journey and Def Leppard will each do 90-minute sets. How many of the songs that will be performed were Top 40, Top 10 or chart-topping hits? You may want to use the calculator on your phone to tally up the total.

Pick six!

At last count, the combined number of guitars owned by Miller, Journey’s Neal Schon and Def Leppard’s Phil Collen and Vivian Campbell exceeds 1,000. Schon currently owns 750, give or take, including the 150 he bought during the pandemic shutdown. At last count, Miller owned more than 400.

Of course, a majority of these guitars stay in high-security storage when their owners are embarked on concert tours, but attendees at Friday night’s concert will likely still see enough different guitars played on stage to stock the wing of a museum.

Until then, here’s what you’ll need to know if you are going to the show.

15 Things to Know

1. The concert’s scheduled starting time is 6 p.m. Friday. The Steve Miller Band will open, followed by Journey. Def Leppard will headline.

2. All gates at Petco Park will open at 4:30 p.m. Friday and early arrival is encouraged. No re-entry will be allowed.

3. Padres parking lots will open at noon Friday for concertgoers with pre-purchased passes. Limited day-of parking will be subject to availability. Its name to the contrary, no tailgating will be permitted in Tailgate Park for this concert.

4. Use of public transportation is strongly encouraged.

Prior to the concert there will be regular San Diego Trolley service on the Green and Blue Lines every 15 minutes, or sooner, to the 12th Street & Imperial Avenue Transit Center. The center is located just  steps away from Petco Park. Green Line riders can de-board at the nearby Gaslamp Quarter Station.

Post-concert trolleys from the 12th Street & Imperial Avenue Transit Center will continue every 15 minutes until at least 45 minutes after the concert’s scheduled 10 p.m. conclusion, then every 30 minutes until the last scheduled trips of the night. Additional trips will be provided as needed, according to a Metropolitan Transit Service representative.

• The last Green Line trolley to SDSU and Santee leaves at 11:36 p.m.

• The last Blue Line trolley to UTC leaves at 11:38 p.m.

• The last Blue Line trolley to San Ysidro leaves at 12:07 a.m. Saturday.

• The last Coaster ride from the Santa Fe depot in downtown San Diego to Oceanside departs Friday at 11:40 p.m.

5. All tickets for the concert are digital and can be found in either the MLB Ballpark app or the Ticketmaster app. Details on how to access or transfer your tickets are available online at mlb.com/padres/tickets/mobile/guide

6. Concertgoers with non-field level “seating bowl” tickets may enter at the following gates:

• The Gaslamp Gate, located at the intersection of K Street. and 7th Avenue.

• The East Village Gate, located at the intersection of K Street and 10th Avenue.

• The Park Blvd. Gate, located at the intersection of Park Boulevard and 10th Avenue.

• The Home Plate Gate, located at the corner of Park Boulevard and Tony Gwynn Drive.

7. Concertgoers with tickets for seats on the field — designated as sections A1-A7 and B2-B6 — must enter at the Gaslamp Breezeway, located at the intersection of 7th Avenue and K Street for field access. Those ticket-holders must obtain a specific field-access wristband before they can gain entry to the field level. Field wristbands are available at the Gaslamp Breezeway. Each ticket must be scanned in order for you to receive a wristband for floor access.

Concertgoers with general admission pit tickets — designated as PITSR or PITSL — must enter at the Park Boulevard Gate located on Park Boulevard and 10th Avenue for pit access. Guests with general admission pit tickets will need a specific pit access wristband before entry. Pit wristbands are available upon entry at the Park Boulevard Gate entrance.  Each ticket must be scanned in order to receive a pit wristband.

8. Concertgoers who purchased a suite can enter, starting at 4:30 p.m. Friday, through any of the non-field level “seating bowl” entrances.

9. No outside food or beverages are permitted, including factory-sealed water bottles and reusable water bottles.

10. Petco Park prohibits backpacks and bags, with the exception of single-compartment clear plastic bags not exceeding 12 inches by six inches by 12 inches, infant and medical bags, and clutches and purses no larger than 5 inches by 7 inches.

11. Petco Park offers mobile lockers, located at the Premier Lot near the pedestrian bridge across from the Home Plate Gate. Locker rentals cost $12 and are cashless. The lockers area will remain open for 30 minutes after the conclusion of the concert.

12. Petco Park is a cashless venue. Credit cards, Padres Pay, Google Pay and Apple Pay are accepted at all concessions locations within the ballpark.

13. No professional cameras or selfie sticks are allowed.

14. Petco Park is a smoke-free facility. Use of tobacco, vaping and e-cigarettes is not allowed inside the stadium. Designated smoking areas will be available at each main gate.

15. Bullhorns, gum, frisbees, drones, hover boards, hula hoops, bubble-making devices and Chapstick are among the numerous items that are prohibited at Petco Park concerts. A complete list is available at: mlb.com/padres/tickets/concerts/prohibited-items